AU784738B2 - Building system and prefabricated wall panels - Google Patents

Description

I 1 P/00/011 Regulation 3.2

AUSTRALIA

Patents Act 1990

ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT Invention Title: "BUILDING SYSTEM AND PREFABRICATED WALL PANELS" The following statement is a full description of this invention, including the best method of performing it known to me/us: FIELD OF THE INVENTION This invention is concerned with a building system and prefabricated wall panels for use therein.

Particularly, although not exclusively, the invention relates to a multi-level building system incorporating prefabricated, prestressed load bearing panels made from a curable cementitious composition.

BACKGROUND OF THE INVENTION Building and construction systems and procedures are governed to a large degree by labour costs. Accordingly, there is an ongoing need to develop new products, procedures and systems within the building and construction industry to achieve labour saving efficiencies.

Over the years there have been many proposals for prefabricated wall panels for use in building construction and these have included both load bearing and non-load bearing panels.

Non load bearing panels are typically used as wall partitions or exterior cladding and are erected between column supported floors as dividing walls. These prefabricated panels are typically of a laminated or composite construction with hollow or low density cores sandwiched between sheets of gypsum board or the like.

Other forms of construction require the use of load bearing walls to achieve the desired structural integrity of a building.

In commercial structures such as warehouses having a large clear span floor area and an elevated roofline, it is not uncommon to construct exterior load bearing reinforced concrete walls in situ as "tilt-up" walls.

This is a relatively cost efficient technique for building structures of this kind but is quite unsuited to multi-storey constructions as generally there is insufficient space for in-situ wall castings and, moreover, access for heavy lifting equipment for large panels can be restricted.

One alternative to the difficulties of constructing load bearing walls in situ is to erect clay brick or masonry block walls but this is slow, labour intensive and incurs substantial costs in application of finishing surfaces such as plastered walls or the application of gypsum sheeting.

Another alternative is off-site manufacture of custom tailored relatively large reinforced concrete wall panels which are constructed individually on an "as required" basis to accommodate particular design considerations for the building and otherwise to accommodate dimensional tolerance variations as building construction progresses. In particular, variations in floor levels give rise to a phenomenon known as building "creep" and this must be accommodated by large dimensional tolerances in panel heights to compensate therefor. The main disadvantages associated with this prior art prefabrication system are the inefficiencies associated with custom tailoring of panels on a job by job basis (which effectively precludes the ability to carry an inventory), the high costs of heavy lifting and transportation equipment incurred between manufacture and on-site installation, and the additional costs incurred in installation of the panels with chocked or wedged supports to 4 compensate for floor level variations.

SUMMARY OF THE INVENTION Accordingly, it is an aim of the present invention to provide an improved building system incorporating pre-fabricated load bearing wall panels and wall panels for use in connection therewith.

The present invention, in one aspect, resides in a building system having a load bearing wall structure, said system including:a plurality of prefabricated prestressed cementitious wall panels adapted in use for edge to edge abutment; and, one or more base locating support members adapted for securement to a base, said base locating support members in use, providing a horizontally and linearly aligned level datum for said load bearing wall structure, said wall panels comprising a pair of prefabricated prestressed cementitious wall panel elements secured in back to back relationship with opposed exterior wall surfaces adapted to receive a decorative finish, each said panel element being supported in a respective support member, said pair of panel elements, in use, being secured by a mechanical connection o 0between aligned connectors on respective inner surfaces of said pair of panel elements.

Preferably said mechanical connection is between respective exposed portions of reinforcing elements anchored in said wall panel elements.

b If required, mechanical connection between said panel elements may S00 be effected by one or more transverse rod-like connectors extending between said aligned connectors.

Additionally or alternatively, mechanical connection between said i. I panel elements may be effected by a curable, flowable material introduced into a cavity between respective pairs of panel elements.

The curable flowable material may comprise a polymeric compound, a cementitious compound, an admixture thereof and, if required the curable flowable material may be cellular or porous when cured.

Suitably said panel elements may include one or more protrusions extending outwardly from an inner surface thereof, said protrusions, in use, being adapted to assist in mechanical connection between respective pairs of panel elements.

If required, the one or more protrusions may be selected from metal anchor members, elongate rib-like members formed integrally with e•* o* *o *e *e *o oo* o said panels or combinations thereof.

The system may also include upper locating brackets to secure respective upper ends of said wall panels to a load bearing structure thereabove.

Suitably said base support members and/or said upper locating brackets include mounting apertures to receivably locate an anchoring member.

The base support members and/or the upper locating brackets may include adjustable levelling means.

Suitably, said base support members and said upper locating brackets are adapted for interengagement.

Preferably said base support members and/or said upper locating brackets are adapted for casting within a respective upper or lower floor slab surface.

Suitably said wall panels may include hollow regions therewithin to locate utility conduits, insulating media or the like.

Preferably said wall panels include upright edges adapted for interengagement between adjacent panels.

The opposed upright edges of said wall panels may comprise interengageable rib and channel formations.

According to another aspect of the invention, there is provided a wall panel element for use in connection with the system and method aspects of the invention, the wall panel element comprising a prestressed cementitious member having at least one exterior finishing surface and otherwise being adapted for back to back mechanical connection to a further wall panel element to form a wall panel.

According to yet another aspect of the invention there is provided a method of erecting a prefabricated prestressed load bearing wall construction, said method comprising the steps of securing to a base, a plurality of base support members to receivably locate prefabricated prestressed wall panels in a predetermined linearly aligned array and characterised in that said support members are secured to said base to define a uniformly level datum over said base.

Suitably said support members are cast into said base, said support members being levelled prior to pouring said base.

Alternatively said support members may be anchored to an upper support surface of said base to define a uniformly level support datum over said base.

Suitably the upper edges of said wall panels are mechanically tied to an upper floor slab by upper locating brackets and/or reinforcing elements extending into said wall panels.

Preferably the upper edges of said wall panels are adapted to be mechanically tied to an upper floor slab subsequently formed thereover and supported by said wall panels.

BRIEF DESCRIPTION OF THE DRAWINGS In order that the invention may be more fully understood and put into practical effect, reference will now be made to preferred embodiments illustrated in the accompanying drawings in which:- FIG 1 is an upright cross sectional view of a wall panel element according to the invention.

FIG 2 is a transverse cross sectional view of a load bearing wall structure comprising a plurality of wall panel elements of FIG 1.

FIG 3 is a cross-sectional view of a wall panel member supported during formation of a floor slab thereover.

FIG 4 is a front elevational phantom view of a load bearing wall structure showing anchored reinforcement and location of interior utility conduits.

FIG 5 shows a transverse cross sectional view of an alternative embodiment of a wall panel element.

FIG 6 shows a base support channel member.

FIG 7 shows an upper locating bracket.

FIG 8 shows a cross sectional view through an intersection of load bearing walls and an intermediate floor slab.

FIG 9 is a transverse cross sectional view of a load bearing wall panel according to the invention.

FIG 10 is an enlarged cross sectional view of an edge joint between adjacent panels.

DETAILED DESCRIPTION OF THE DRAWINGS In FIG 1 there is shown an upright cross sectional view of a panel 1 element according to one aspect of the invention.

Panel 1 comprises a sheet of flowable curable cementitious material such as concrete. The panel 1 has smooth finishing face 2 adapted to receive a decorative finish such as plaster, paint or other suitable finishing material.

The panel is reinforced by prestressing strand and/or steel reinforcing mesh 3 and, if required, a plurality of spaced reinforcing ribs or trusses 4 each containing a reinforcing bar (not shown) if so required.

Also secured into the panel 1 is a plurality of spaced undulating steel reinforcing members 5 with a portion 5a encapsulated within panel 1 and a loop portion 5b protruding from the rear face 6 of panel 1. The apertures 7 formed by protruding loop portions 5b are aligned, the purpose of which will be explained later.

FIG 2 shows in plan view a transverse cross section of a load bearing wall. Wall 8 comprises a plurality of panel elements of the type shown in FIG 1 or, as shown in FIG 2, substantially identical wall elements without reinforcing ribs or trusses 4.

For the sake of simplicity, like reference numerals are employed for like features.

The wall 8 is formed from aligned pairs 1 a, lb of wall elements 1 arranged in edge to edge abutting relationship. The upright edges 9 are feathered to allow a smooth plastered joint between adjacent panels.

Panels 1 a, 1 b are spaced as shown to form an internal cavity within with respective loop portions 5b overlap. The pairs of panels la, 1 b are secured by a transverse reinforcing rod 11 extending through the overlapped loop portions 5b of respective adjacent panels 1 a, 1 b.

Spaced reinforcing rods 12 extend vertically through the cavity and are tied at their respective lower ends into a floor structure (not shown) at their respective upper ends to a floor structure thereabove (also not shown). If required, cavity 10 may be filled with a flowable concrete grout to create an integrally formed reinforced concrete structure. Alternatively, the cavity 10 may be left as an enclosed air space or an insulating material may be inserted therein and the spacing of the panels may be adjusted to suit acoustic requirements of the wall.

FIG 3 illustrates the erection of a double skinned load bearing wall according to the invention.

In the formation of lower floor slab 15, channel-like base support members shown generally at 16 are cast into the floor slab. Before pouring the slab 15, the base support members are aligned linearly and levelled by a laser level or the like to define a uniformly level datum surface to support the prefabricated panel elements 16, 17.

After the slab 15 has been poured and finished, wall elements 17, 18 are located in respective channels 16 and their respective upper ends 19 are located in an upper mounting bracket 20 which is connected to a temporary brace or prop 21 removably secured to slab Although not shown steel reinforcing members extend within a W 1P 11 cavity 22 between spaced panel elements 16, 17 and are tied at a lower end to reinforcing in the floor slab 15 such as starter bars or the like and also tied at an upper end to reinforcing positioned above formwork or the like for a proposed upper floor slab 23. When floor slab 23 is cast the upper and lower floors are integrally formed with a load bearing wall structure therebetween. Once upper floor slab 23 has been poured and allowed to cure, props or braces 21 are removed.

If required, utility conduits such as electrical wiring, data cables, telephone cables and water pipes can be installed on an inner face of one panel before erecting an opposite panel to define a cavity 22 therebetween. The cavity 22 may include preformed slabs of foam polymer insulation such as polystyrene, polyethylene, PVC, polyurethane or like cellular polymeric materials or an insulating core may be formed by filling the cavity 22 with a foamable polymeric liquid such as polyurethane or a low density cementitious material such as a foamed cementitious grout with or without low density particulate fillers.

As an alternative to casting the support channels 16 into floor slab 16 as shown in the encircled junction between slab 15 and wall panels 17, 18, channels 16 can be secured on the surface of slab 15, as shown in the enlarged encircled region, to provide alignment and a uniformly level datum for all of the wall panels on slab FIG 4 shows a front elevational phantom view of a wall structure including wall panels 20a incorporating utility conduits and reinforcing 12 bars extending between upper and lower floor slabs 21, 22.

Prefabricated wall panel 20a, typically measuring say, 2700mm to 3000 mm high and 1200 mm wide comprises opposed exterior finish surfaces (not shown) and spaced reinforcing ribs or trusses 23 defining cavities 24 therebetween. Suitably wall panel 20a may be formed as a single unitary structure or it may be comprised of a pair of joined panel elements.

Located within cavities 24 are electrical conduits 25 which extend through switch mounting apertures 26 formed in either or both outer faces. Similarly, a water conduit 27 terminates in a fitting 28 aligned with corresponding aperture 29 in an exterior face of the panel Conduits 25 and 27 may be located within wall cavities 24 prior to or during erection of the wall panels. Alternatively conduits 25 and 27 may be positioned within wall cavities 24 after erection of the wall panels but before formation of the upper floor structure.

Reinforcing bars (not shown) may be located within at least some of wall cavities 24 and these bars are adapted for connection to the steel reinforcing structures in the upper and lower floor slabs to ensure the structural integrity of the building structure. For example, the bars may be tied or welded at their lower ends to starter bars (not shown) extending upwardly from the surface of lower floor slab 22. Similarly the upper ends of the bars may extend into the region of upper slab 21 for securing to the slab reinforcement (not shown) before the slab is formed.

MIEM-

13 Alternatively, the reinforcing bars may comprise conventional helically threaded rods or a coarsely threaded rod with flattened parallel side faces such as "Reid Bar" or "Diwydag Bar". These threaded bars may be coupled to adjacent reinforcing structures by screw threaded couplings such as anchor plates and nuts or long union nuts (not shown) for coaxially coupling of threaded bars. If required, the cavities 24 may then be filled with a flowable curable cementitious substance before formation of the upper floor structures.

The junction 30 between adjacent panels may be filled with a sealing composition and the upper edges of adjacent panels 21a are secured together by a bracket 30 which in turn may be secured to the reinforcing structure of slab 21 above.

FIG 5 shows a transverse cross sectional view of a single skinned wall panel according to one aspect of the invention.

Panel 35 comprises a skin or wall 36 having an outer finish surface 37 and an inner surface 38 from which longitudinal ribs 39 protrude.

Ribs 39, being of a trapezoidal cross section with undercut side edges 40 provide a strong mechanical key to permit bonding of a pair of such panel elements back to back with abutting ribs when a flowable cementitious grout or the like is introduced into cavities formed between opposed skins 36 and then allowed to cure.

Panel elements 35 include reinforcing in the form of metal mesh 41 and spaced upright reinforcing bars or prestressing strand 42.

14 Fig 6 shows a base support bracket 50 supporting portions of spaced.panel elements 51 shown in phantom.

Base support bracket 50 comprises a pair of spaced channel members 52 secured to a transverse bracket 53 having a central aperture 54 therein. Central aperture 54 is adapted to receive a threaded reinforcing bar (not shown) such as a starter bar extending upwardly from the floor slab structure therebeneath.

Bracket 50 may be engaged over an upwardly extending starter bar before the slab is cast. As the starter bar is threaded, bracket may be vertically adjustable by screw threaded nuts secured to the threaded bar. Where brackets 50 are adjustably mounted, the location of the entire load bearing wall layout may be positioned, aligned and uniformly level base datum established for wall panels to be located in the channel members 52. After the brackets 50 are secured to the slab reinforcing and aligned and accurately levelled by a laser levelling system or the like, the lower floor slab may then be poured and trowelled using the upper edges 55 of the channel members 52 as a reference datum to obtain a slab surface having a substantially closer tolerance than hitherto possible with conventional slab pouring and levelling procedures. Before pouring and levelling the concrete floor, a cover such as masking tape is secured over the channel aperture or a removable expanded polystyrene plug is inserted to prevent ingress of concrete. This improved control of floor levels substantially diminishes "floor creep" commonly encountered in conventional multi-storey constructions.

As an alternative, bracket 50 may be secured to a completed floor slab by securing over a starter bar protruding from the slab structure.

Levelling of the brackets over the surface of the floor slab to obtain a uniformly level base datum for erection of wall panels may be achieved by selective packing of the bracket Although in FIG 6 the embodiment illustrated is suitable for double skinned wall systems, it readily will be apparent to a person skilled in the art that a single channel bracket may be adapted to suit a unitary wall panel system.

FIG 7 shows an upper locating bracket 60 which may be used in conjunction with the base support bracket of FIG 6 in erection of wall panels.

As shown, upper locating bracket 60 comprises a pair of spaced downwardly facing channels 61 secured to a transverse bracket 62 having protruding flanges 63. Apertures 64 are located generally centrally of bracket 62 and flanges 63 and, like base support bracket of FIG 6, channel members 61 locate the ends of wall panel elements in a predetermined spaced relationship.

Typically, upper locating brackets 60 are mounted on the upper ends of panels 65, bridging the joint between adjacent panels, during erection and the panels are supported in a vertical position as shown in FIG 3 by one or two props or braces (not shown) secured at its (or their) 16 upper end to a respective flange 63 by a nut and bolt, the props or braces being secured at its (or their) lower end to the supporting floor slab by anchor bolts or the like.

An upper floor structure tied to bracket 60 may then be formed by erecting formwork and reinforcing followed by pouring of the concrete floor slab. After the upper floor slab has cured sufficiently, the props or braces are removed as the slab is supported on the load bearing wall structure therebeneath. As an alternative to a unitary cast floor slab, the floor flab may comprise a plurality of pre-cast concrete beams in the formation of the upper floor slab.

FIG 8 is a cross-sectional view of an intersection between a floor slab and upper and lower load bearing wall structures.

In the construction shown, the upper and lower load bearing wall structures 70, 71 respectively are formed as double skinned wall panels 72 of the type generally shown in FIG 1 with an outer finish face 73 and an inner face 74 from which a series of steel wire or rod loops project. Adjacent portions of loops of adjacent panel elements 72a are secured within the cavity 76 between adjacent panel elements by ties or the like 77, which, if required, could also tie upright reinforcing bars 78 to the structure.

Erection of the wall structure is generally in accordance with the earlier description relating to FIGS 1, 3, 4, 6 and 7 in that lower wall structure 71 is erected followed by floor slab 79 and then upper wall structure In formation of the floor slab 79, a threaded reinforcing bar 80 is mounted in the central aperture 64 of upper mounting bracket 60 atop lower wall panel elements 72a by screw threaded nuts 81 secured on each side of transverse bracket 62. Portion of the threaded bar extends into lower wall cavity 76 and may be tied or otherwise secured to reinforcing loops 75 and/or reinforcing bars 78. In cyclone rated regions, the lower end 82 of threaded bar 80 may be coupled by a threaded coupling such as a long nut or other coupling means to a reinforcing tendon tied directly or indirectly into the building foundations.

Floor slab 79 is then constructed with the upper portion 83 of threaded bar 80 extending above the upper surface in the form of a starter bar. A base support bracket 50 of the type generally shown in FIG 6 is mounted via aperture 54 on the exposed portion of bar 80 and, via threaded nuts 84 is adjusted to a desired height at a predetermined level to obtain a uniformly level datum surface in the base of each channel member 52 for the bases of wall panel elements 72a as well as a level datum level for the slab upper surface coincident with the upper edges 55 of channel members 52.

Either before the formation of slab floor 79 or at the same time, a flowable cementitious grout is pumped into the wall cavity 76 of lower wall structure 71 and vibrated if required to minimize voids. Ties 77 support the thin walled panel element 72a against outwardly directed 18 hydraulic forces of the liquid grout until it begins to cure. Alternatively, panel elements 72a may be secured against this hydraulic pressure as described in relation to the embodiment of FIG 1.

Floor slab 79 with internal mesh and/or bar reinforcing 85 is then formed to provide a base from which to continue erection of load bearing walls and the construction process as generally described above is repeated to obtain a multiple storey structure as required.

FIG 9 shows an alternative embodiment in the form of a unitary load bearing wall structure.

As shown FIG 9 represents a transverse cross sectional view of a unitary double skin wall panel 90 having opposed finish surfaces 91 and spaced hollow cavities or cores 92 between opposed outer skins 93.

The intermediate regions 94 between opposed skins 93 function as spacing and reinforcing ribs and may include steel reinforcing bars if required. The panels are otherwise reinforced by steel mesh and/or prestressing strands 95 and/or upright reinforcing bars 96.

In construction of a building, the panels 90 may be secured by single channel base supports (not shown) and single channel upper support brackets (also not shown). Reinforcing bars may extend through hollow cores 92 which also may be filled with cementitious grout if required.

FIG 10 shows schematically an enlarged view of an enlarged view of upright edge abutment between adjacent single or double skin wall structures.

Wall panels 100, 101 may have, on opposite upright edges thereof, a longitudinally extending rib 102 (shown in phantom) and a longitudinally extending channel 103 adapted to receive a rib 102 of an abutting adjacent panel.

Preferably however the wall panels have longitudinally extending channels 103 extending along opposite edges thereof, together defining a hollow chamber 105 when adjcent panels are abutted. Recessed corners on the upright edges of each panel together form a shallow channel 106 bridging the joint between adjacent panels.

When channels 106 are filled with a flexible polymeric sealant, the hollow chamber 105 forms a very effective acoustic barrier between adjacent panels.

The free edges of panels 100, 101 are feathered to allow taping and/or skin coating with plaster to obtain a seam free joint 104 between adjacent panels.

It readily will be apparent to a person skilled in the art that many modifications and variations may be made to the various aspects of the invention without departing from the spirit and scope thereof.

For example, while FIGS 1 9 illustrate various preferred embodiments, individual features described in relation to one embodiment may be employed with alternative embodiments.

It also will be readily apparent to a skilled addressee that the various aspects of the invention offer substantial advantages over known building systems and building panels for use inconnection therewith.

In addition to load bearing walls for multi-storey building for which the system according to the invention is particularly suited, the other applications may include landscaping wall structures, acoustic roadway panels and the like. The panels, suitably adapted, may also be employed as outer cladding on low and high rise buildings.

The use of relatively small single and/or double walled panels of predetermined dimensions avoids the necessity (and cost) of heavy lifting equipment at a manufacturing site and on the building site. Similarly, the use of smaller panels of lower mass simplifies both handling and transportation of the panels.

A significant advantage is the ability to utilise a system embodying full load bearing walls which are less expensive to erect than prior art wall structures and which permit accurate levelling of standard sized panels without the necessity to construct specially tailored panels to compensate for progressive "floor creep" as the building progresses. This means that a panel fabricator can hold a large inventory of standard panels to accommodate fluctuations in supply and delivery of the panels to a construction site.

The double skinned wall panel system allows construction of load bearing walls of varying thickness acoustic ratings and load bearing capacity as required with ready incorporation of reinforcing and utility 21 conduits within the wall structure during erection.

The composite panel structure shown generally in FIGS 2 and 8 also may be utilised to construct load bearing beams. For example a plurality of panel elements may be erected at a spacing to define a beam of desired thickness. The reinforcing members associated with each panel are tied as generally shown in FIGS 2 and 8 and reinforcing mesh, rods and/or strand are secured within the space between the panels. A flowable high strength concrete grout is pumped into the space between the panels to encapsulate the reinforcing members and, if required, is vibrated to remove air pockets. The resultant structure is a load bearing beam of high structural integrity and may be employed to reduce the number of support columns in a building structure.

The system and panels according to the various aspects of the invention are able to be employed in single storey domestic dwellings and commercial buildings as well as mid-rise and high rise multi-storeyed structures allowing immense architectural design flexibility whilst retaining maximum structural integrity.

The compact nature of the wall panel elements and their relatively low mass when compared with a prefabricated concrete wall permits great efficiencies to be achieved in transportation and handling costs.

Throughout this specification and claims which follow, unless the context requires otherwise, the word "comprise", and variations such as "comprises" or "comprising", will be understood to I_ 22 imply the inclusion of a stated integer or group of integers or steps but not the exclusion of any other integer or group of integers.

6h.-

Claims (24)

1. A building system having a load bearing wall structure, said system including:- a plurality of prefabricated prestressed cementitious wall panels adapted in use for edge to edge abutment; and, one or more base locating support members adapted for securement to a base, said base locating support members in use, providing a horizontally and linearly aligned level datum for said load bearing wall structure, said wall panels comprising a pair of prefabricated prestressed cementitious wall panel elements secured in back to back relationship with opposed exterior wall surfaces adapted to receive a decorative finish, each said panel element being supported in a respective support member, said pair of panel elements, in use, being secured by a mechanical connection between aligned connectors on respective inner surfaces of said pair of panel elements.

2. A system as claimed in claim 1 wherein said mechanical connection is between respective exposed portions of reinforcing elements anchored in said wall panel elements.

3. A system as claimed in claim 1 or claim 2 wherein mechanical connection between said panel elements is effected by one or more rod-like connectors extending between said aligned connectors.

4. A system as claimed in claim 1 wherein mechanical connection 00 between said panel elements is effected by a curable, flowable material introduced into a cavity between respective pairs of panel elements.

5. A system as claimed in claim 2 or claim 3 wherein a curable, flowable 24 material is introduced into a cavity between respective pairs of panel elements.

6. A system as claimed in claim 4 or claim 5 wherein the curable flowable material comprises a polymeric compound, a cementitious compound, an admixture thereof and, if required, the curable flowable material may be cellular or porous when cured.

7. A system as claimed in any preceding claim wherein said panel elements each include one or more protrusions extending away from an inner surface thereof, said protrusions, in use, being adapted to assist in mechanical connection between respective pairs of panel elements.

8. A system as claimed in claim 7 wherein said one or more protrusions are selected from metal anchor members, elongate rib-like members formed integrally with said panels or combinations thereof.

9. A system as claimed in any preceding claim including upper locating brackets to secure respective upper ends of said wall panels to a load bearing structure thereabove.

10. A system as claimed in any preceding claim wherein said base locating support members and/or said upper locating brackets include mounting apertures to receivably locate an anchoring member. 20

11. A system as claimed in any preceding claim wherein said base locating support members and/or the upper locating brackets include adjustable levelling means.

12. A system as claimed in any preceding claim wherein said base locating support members and said upper locating brackets are adapted for interengagement by a coupling member extending therebetween.

13. A system as claimed in any preceding claim wherein said base locating support members and/or said upper locating brackets are adapted for casting within a respective upper or lower floor slab surface.

14. A system as claimed in any preceding claim wherein said wall panels include hollow regions therewithin to locate utility conduits, insulating media or the like.

A system as claimed in any preceding claim wherein, in use, said wall panels include upright edges adapted for interengagement between adjacent panels.

16. A system as claimed in claim 15 wherein said opposed upright edges of said wall panels comprise interengageable rib and channel formations.

17. A system as claimed in claim 15 wherein said opposed upright edges of said wall panels comprise channel formations, in use, together forming hollow chambers between abutting edges of adjacent wall panels. o 15

18. A method of erecting a building system according to any one of claims 1 to 17, said method comprising the steps of securing to a base, a plurality of *base locating support members to receivably locate prefabricated prestressed wall panels in a predetermined linearly aligned array and characterised in that said support members are secured to said base to define a uniformly level datum over said base.

19. A method as claimed in claim 18 wherein said support members are cast into said base, said support members being levelled prior to pouring said base.

A method as claimed in claim 18 wherein said support members are anchored to an upper support surface of said base to define a uniformly level 26 support datum spaced from said base.

21. A method as claimed in any one of claims 18 to 20 wherein upper edges of said wall panels are adapted to be mechanically tied to an upper floor slab subsequently formed thereover and supported by said wall panels.

22. A method as claimed in any one of claims 18 to 21 wherein upper edges of said wall panels are mechanically tied to an upper floor slab by upper locating brackets and/or reinforcing elements extending into said wall panels.

23. A building system substantially as hereinbefore described with reference to the accompanying drawings.

24. A method of erecting a building system substantially as hereinbefore described with reference to the accompanying drawings. DATED this Seventeenth day of March 2006. PETER FRENSEMEYER By His Patent Attorneys FISHER ADAMS KELLYS