Background of the Invention

[0001] The present invention generally relates to formwork for structural walls and a method of constructing same.

Description of the Prior Art

[0002] The reference in this specification to any prior publication (or information derived from it), or to any matter which is known, is not, and should not be taken as an acknowledgment or admission or any form of suggestion that the prior publication (or information derived from it) or known matter forms part of the common general knowledge in the field of endeavour to which this specification relates.

[0003] Panelised formwork systems have been used in the construction industry for approximately 35 years. One of the earliest approaches used a panel system consisting of polystyrene studs clad with fibre cement sheeting. Vertical voids were formed between the studs which were kept below the top of the panel, forming a void for a ring beam. Reinforcing rods were installed vertically and horizontally into the panels before filling the panels with concrete. This provided a structural wall suited for housing in cyclone regions and many homes were built in Queensland, Australia and overseas with this system.

[0004] Recognising a need for fire and sound rated walls for duplexes and multi resident structures, steel studs were introduced into the panel system, dramatically changing the culture and methodology of builders, constructing high rise apartment buildings and other structures requiring fire and sound rated walls. In the following years, many projects from two stories to 30 were constructed using this system throughout Australia and overseas.

[0005] The wall system continued to evolve in the following years, replacing the steel studs with a combination of aluminium and plastic and refining the quality of finishes and performance of the system generally. The emergence of this system also created a lot of attention and ultimately copycat systems emerged. Other systems included extruded plastic panel systems that have limitations, regarding fire rating, finishes and difficulty installing reinforcing steel. [0006] Today, the building industry uses panel formwork systems extensively and is aware of the strengths and weaknesses of each system in the market. Recent events in the industry have had repercussions, exposing a number of problems common to the known systems. These events include fire in high rise buildings caused by flammable external cladding, and subsidence and localised structural failure in multistorey buildings caused by defective reinforcing installation. These and other issues have caught the attention of engineers and building certifiers, and in turn, insurance companies, who carry the risk of failed building methodology.

[0007] Fire risk is one of the most pressing issues with the current systems. Fibre cement sheet and plastic are the external faces of all the systems mentioned above. Fibre cement while noncombustible disintegrates and becomes a fall hazard in the event of a fire. Meanwhile, plastic can be combustible and is considered unacceptable by certifiers even as connectors embedded in concrete walls.

[0008] The installation of reinforcing steel has always also been a problem with these systems. Dropping in vertical steel reinforcing bars and then threading horizontal steel bars through the panel system cannot always be achieved at centres required by engineers nor can they be tied effectively, particularly at comers and tee intersections, as prescribed in the regulations.

[0009] Not only is the installation of reinforcing steel difficult, but it is also rarely possible for the engineer to inspect and certify the steel reinforcing prior to pouring concrete into the panel system. This has made them reluctant to specify these products or if they do, far more particular about the installation of them

[0010] Finally, issues common to all the above systems are the application and quality of finishes both internal and external. After panels are erected, services are often installed requiring opening of the faces, installing the services and patching. Generally, with few exceptions, the internal faces are sheeted over with plasterboard while the external faces are rendered with acrylic finishes.

[0011] Accordingly, an alternative system is desirable that addresses one or more of the above or other related problems, or at least provides a cost effective alternative. Summary of the Present Invention

[0012] According to a broad aspect of the invention, there is provided a formwork system, comprising: a plurality of panels, comprising at least a first panel and a second panel, wherein each of the panels comprises a first edge and a second edge, the first and second edges being on opposite sides of the panel; an elongate joiner configured to connect the first panel to the second panel by coupling with the first edge of the second panel and the second edge of the first panel; and, a plurality of brackets, each of the brackets having two coupling portions, the coupling portions being located at opposite ends of the bracket, wherein each coupling portion is configured to couple with the elongate joiner.

[0013] In an embodiment, the panels are substantially identical to one another.

[0014] In an embodiment, the panels are made from a material that can be cut, rebated, and/or readily shaped in another way once at a building site.

[0015] In an embodiment, the panels are made from a non-combustible material.

[0016] In an embodiment, the panels are made from at least one of: a magnesium oxide board; a gypsum board; a fibre reinforced cement board; a plywood board; a composite board; and, a laminate including at least one of the aforementioned boards.

[0017] In an embodiment, at least one of the panels includes reinforcement made from at least one of: fibreglass; metal stiffeners; and, sheet metal.

[0018] In an embodiment, the first edge and the second edge are tapered and/or comprise a rebate.

[0019] In an embodiment, the panels are provided with the elongate joiner coupled to the second edge.

[0020] In an embodiment, a cladding is folded and bonded to a surface of the coupled panel and elongate joiner.

[0021] In an embodiment, the elongate joiner has an I-shaped cross section comprising a central section and two end sections arranged substantially normal to the central section, wherein an additional flange extends from the central section at a location between the end sections but offset so as to be closer to one of the end sections, thereby forming a narrow channel between the flange and the end section to which it is closest.

[0022] In an embodiment, the flange is longer than the end sections.

[0023] In an embodiment, the flange extends from both sides of the central section so that the cross section of the elongate joiner is symmetrical.

[0024] In an embodiment, the bracket has a slot at each end configured to accommodate a part of the end section of the elongate joiner.

[0025] In an embodiment, the bracket couples to the elongate joiner by being inserted into the narrow channel.

[0026] In an embodiment, the bracket is in the form of a short I-beam.

[0027] In an embodiment, the formwork system further comprises an insulation support that is configured to couple with the elongate joiner.

[0028] In an embodiment, the formwork system further comprises a bottom track configured to abut a substrate and to couple with the first edge of the first panel or an end of the first panel.

[0029] According to another broad aspect of the invention, there is provided a permanent formwork for a concrete wall, comprising an outer form and an inner form, each of the forms comprising: a plurality of panels, comprising at least a first panel and a second panel, wherein each of the panels comprises a first edge and a second edge, the first and second edges being on opposite sides of the panel; and, an elongate joiner configured to connect the first panel to the second panel by coupling with the first edge of the first panel and the second edge of the second panel; wherein the formwork further comprises a plurality of brackets, each of the brackets having two coupling portions, the coupling portions being located at opposite ends of the bracket, wherein each coupling portion is coupled with the elongate joiner of one of the forms, thereby connecting the outer form to the inner form.

[0030] In an embodiment, the permanent formwork is constructed using the formwork system as defined herein. [0031] According to another broad aspect of the invention, there is provided a method of constructing a wall, comprising the steps of: providing a bottom track at a location that is to be a bottom of the wall; providing a first panel and placing a first edge of the first panel into the bottom track; providing an elongate joiner and fitting to a second edge of the first panel; providing a plurality of brackets and coupling the brackets to the elongate joiner; providing a second panel and placing a first edge of the second panel into the elongate joiner, thereby creating at least part of a first form; arranging reinforcing steel adjacent the first form and securing in place; repeating steps above to begin assembly of a second form in a location adjacent the first form, so that the reinforcing steel is located therebetween; coupling the brackets of the first form with the elongate joiner of the second form; and continue assembly of the second form in accordance with a step above.

[0032] In an embodiment, the method is performed using the formwork system as defined herein.

[0033] It will be appreciated that the broad forms of the invention and their respective features can be used in conjunction and/or independently, and reference to separate broad forms is not intended to be limiting. Furthermore, it will be appreciated that features of the method can be performed using the system or apparatus and that features of the system or apparatus can be implemented using the method.

Brief Description of the Drawings

[0034] Various examples and embodiments of the present invention will now be described with reference to the accompanying drawings, in which: -

[0035] Figure 1 is an upper perspective view of a section of a formwork system according to an embodiment of the invention;

[0036] Figure 2 is side perspective view of the formwork system from Figure 1;

[0037] Figure 3 is an angled perspective view of the formwork system from Figure 1;

[0038] Figure 4A is a schematic side view of a panel and an elongate joiner preassembled with cladding in accordance with another example embodiment of the invention; [0039] Figure 4B is a perspective view of the panel, elongate joiner and cladding from Figure 4A;

[0040] Figure 5 is an upper perspective view of a section of another embodiment of the formwork system with reinforcing and a brace installed;

[0041] Figure 6 is an angled perspective view of the formwork system from Figure 5;

[0042] Figure 7 is a side perspective view of a bracket according to an example embodiment of the invention;

[0043] Figure 8 is an upper perspective view of a bracket according to an alternative example embodiment of the invention;

[0044] Figure 9 is a perspective view of an elongate joiner according to an example embodiment of the invention;

[0045] Figure 10 is a perspective view of a bottom track according to an example embodiment of the invention;

[0046] Figure I l a side perspective view of a section of a formwork system according to another example embodiment of the invention;

[0047] Figure 12 is a side perspective view of another section of the formwork system from Figure 11;

[0048] Figure 13 is a schematic side view of a section of a formwork system according to another example embodiment of the invention, where insulation is fitted;

[0049] Figure 14A is a schematic side view of a section of a formwork system according to another example embodiment of the invention, where metal cladding is fitted;

[0050] Figure 14B is a schematic side view of Detail A from Figure 14A;

[0051] Figure 15 is a schematic side view of a section of a formwork system according to another example embodiment of the invention; [0052] Figure 16 is a schematic side view of a base assembly for use with the formwork system from Figure 15;

[0053] Figure 17 is a perspective view of an elongate joiner from Figure 15;

[0054] Figure 18A is a top view of a bracket from Figure 15; and,

[0055] Figure 18B is a front view of the bracket from Figure 15.

Detailed Description of the Preferred Embodiments

[0056] The following modes, given by way of example only, are described in order to provide a more precise understanding of the subject matter of a preferred embodiment or embodiments.

[0057] In the Figures, incorporated to illustrate features of an example embodiment, like reference numerals are used to identify like parts throughout the Figures.

[0058] An example of a formwork system according to the invention will now be described. In this example, the formwork system includes a plurality of panels, each having a first edge and a second edge being on opposite sides of the panel. An elongate joiner can be used to connect a first one of the panels to a second one of the panels by coupling two of the edges.

[0059] The formwork system also includes a plurality of brackets that can couple with the elongate joiner. Each of the brackets has two coupling portions at opposite ends. In this way, the panels and the elongate joiners can be used to create an outer form and an inner form that are connected to one another using the brackets.

[0060] Advantageously, the system is very simple, requiring as little as three different types of extruded components and flat sheets of material. All of these components can be made available off the shelf and at short notice, delivered flat packed to site. This may allow for significant reductions in cost and time when compared to prior art systems.

[0061] A number of other features will now be described, which may be optional or advantageous aspects of some example embodiments.

[0062] In one preferred embodiment of the invention, the panels may be substantially identical to one another. This can allow the ordering, manufacturing, and assembly process to be extremely simple. All that is required is a given quantity of panels, which are then assembled as required.

[0063] Prior art systems would typically require a team of drafters to generate workshop drawings to panelise each wall within the building. These drawings are then sent to the client for checking and confirmation of order, before the panels are manufactured by the factory. Every panel on every floor has an address in the building. In a typical project, this may take eight weeks or more from initial contact until the first delivery, with numerous steps in which mistakes may easily occur.

[0064] In contrast, the present system can eliminate the need for the extra drafting, with engineering and/or architectural drawings being sufficient. Pallets of flat packed panels can be provided, with no set location of any particular panel in the building. Manufacturing is simplified and order times reduced, as stock can be already manufactured in advance and ready to be delivered as soon as an order is received. That is, specific workshop drawings are not required and special manufacturing is also not required.

[0065] In some example embodiments, the system may also allow for simplified and cheaper transport of components to site. Described below is one example that illustrates a possible saving in delivery of required materials to a work site.

[0066] Delivery of prior art systems may involve standard panels with a size in the order of 1200mm x 2700mm x 20mm, which would be loaded up to six high on a pallet. A standard 12m semi-trailer tray would only be able to carry a maximum of eight pallets, which equates to approximately 155m ² of formwork panels. A typical building requiring 12,000m ² of panels would therefore require 77 trucks to be loaded, delivered and unloaded at the site, possibly requiring traffic management with each delivery.

[0067] In contrast, the present system may allow for panels to be flat packed, with sheets of 600mm x 2700mm x 20mm stacked on pallets up to 20 sheets high. 32 pallets would be able to be carried by a standard semi-trailer, which would be limited by weight, not volume. This is the equivalent 1,037m ² of wall formwork, meaning that the same building requiring 12,000m ² of wall form work would now require only ten trucks loaded, delivered and unloaded at the site. [0068] Similar advantages may also be realised in relation to required area on site for storing materials prior to assembly. For example, prior art systems may require for a truckload of 155m ² of panels on pallets an area of about 36m ² to be stored at the source or on-site before installation. In contrast, the present system for a similar panel are could require as little as 5m ² of space, thereby freeing up significant working area.

[0069] The system may also allow for simplified pouring of concrete once the formwork system is assembled. Described below is one example that illustrates possible differences and advantages of the present system over the prior art.

[0070] Commonly used prior art panel systems are faced with 6mm fibre cement sheets attached to studs at less than 150mm centres. This tests the spanning capacity of the fibre cement sheet and the glue line bonding it to the studs. Blowouts do occur and can be costly in extra time taken to rectify, as the wall filling process needs to move to another area, then return later to the fixed blowout section.

[0071] The slump of the concrete being poured into the walls in these prior art systems also needs to be carefully managed. The procedure in filling these panels is to bring the level of concrete higher in progressive passes of approximately Im, depending on the slump of the concrete.

[0072] In contrast, the present system may allow for a more open core to allow concrete to flow more freely. The panels used may be robust 20mm thick sheets and more able to resist the forces of wet concrete. They are physically held in place by the elongate joiners throughout the filling process. The brackets restraining the elongate joiners may also be spaced far enough apart to allow the free flow of high slump concrete through the walls, and around comers and tees, requiring less pump time and labour.

[0073] Preferably, the panels are made from a material that can be cut, rebated, and/or readily shaped in another way once at a building site. This may complement the feature previously described where all the panels are substantially identical, as any different panel that may be required can simply be prepared on site. For example, panels may be cut to a shorter length, or ends chamfered to construct a comer where two walls meet. [0074] In a preferred embodiment, the panels may be made from a non-combustible material. This is particularly advantageous when compared to prior art system where fire related issues for fibre cement and plastic formwork systems continue to be a problem for certifiers and insurance companies. This is a problem for which the full extent is only beginning to be realised. Using non-combustible panels in the present invention is possible and addresses these issues.

[0075] In one specific example, the panels may be 20mm thick and have a 2 hour fire rating on their own. This is on both faces of the finished wall, and inside the wall will be at least a 100mm reinforced concrete core.

[0076] In one specific example embodiment, the panels may be made from a magnesium oxide board or similar. For example, this may be a material with a magnesium oxide (MgO) base, magnesium sulphate base (MgSCU), these or other materials that are substantially chloride free, or other related materials.

[0077] Such a material may be non-combustible as described previously, while also having the required strength to withstand a significant weight of concrete. For example, a panel made from one of these materials may be only 20mm thick yet able to span a 600mm gap while still being strong enough to withstand the concrete pressure during pouring. It will be appreciated, however, that other materials could alternatively be used, such as a gypsum based laminate or similar.

[0078] Other suitable panel materials include fibre reinforced cement board; plywood board; composite board, or laminates including these boards and/or the aforementioned magnesium oxide or gypsum boards. In some embodiments, the panels may include reinforcement which may include fibreglass, metal stiffeners; and, sheet metal. The reinforcement may be provided in a layer or embedded into the panel material. For example, a sheet metal layer may be laminated with a magnesium oxide board to provide a reinforced panel.

[0079] In one example embodiment, the first edge and the second edge may be tapered and/or comprise a rebate. Such a feature allows the panel and the elongate joiner to form a substantially planar outer surface. A taper can also assist in assembling the panel and elongate joiner, by guiding the panel into place, but coupling securely once fully inserted. [0080] In another example, the panels may be provided with the elongate joiner already coupled to the second edge. Additionally, this could also allow for cladding to be folded and bonded to a surface of the coupled panel and elongate joiner, such that these components are pre-assembled offsite to allow for simpler and faster final assembly. Such a system may be particularly advantageous as it can eliminate the need to access the external surface following construction, thereby removing the need for external scaffolding for example, resulting in significant labour and cost savings.

[0081] In prior art systems, extruded plastic and fibre cement panels are frequently over sheeted with plasterboard on the internal faces, then set and painted to achieve acceptable finishes to the walls. External finishes are sealed, joints set and then rendered with an acrylic render system.

[0082] In contrast, the above features of certain example embodiments of the present system may allow for faces to be flat and thereby potentially removing the need to re-sheet. In one specific example embodiment of the present system, the elongate joiners may sit 1mm below the face of the panel once assembled. This leaves a 15mm wide gap on the face that can be set without tape, at an easy to reach height, to provide a high class finish internally, ready to paint. That is, the present system may remove the need for any over sheeting.

[0083] Externally the wall can be sealed, and joins set and then rendered using an acrylic render system as required. Alternatively or additionally, aluminium cladding may be installed as the external wall face is assembled.

[0084] In some example embodiments, the elongate joiner may have an I-shaped cross section. This can include a central section and two end sections arranged substantially normal to the central section. An additional flange may extend from the central section at a location between the end sections but offset so as to be closer to one of the end sections, thereby forming a narrow channel between the flange and the end section to which it is closest. This narrow channel can be used for coupling with the brackets, while the wider channel can be used for coupling with the panels.

[0085] The flange may be longer than the end sections, providing a substantial surface against which the bracket can abut. Preferably, the flange may also extend from both sides of the central section so that the cross section of the elongate joiner is symmetrical. In this way, the elongate joiner is easier to install, as there are multiple possible orientations. It also removes the need for a mirror image version to be produced for the opposite form, keeping the manufacture and ordering process as simple as possible.

[0086] In some examples, the bracket may have a slot at each end configured to accommodate a part of the end section of the elongate joiner. In other examples, however, the bracket may couple to the elongate joiner simply by being inserted into the narrow channel. For example, the bracket may be in the form of a short I-beam, where an end portion is inserted into the narrow channel of the elongate j oiner. Alternatively, a slot may allow this I-beam to be installed at 90° relative to this example, which may assist with concrete flow.

[0087] In one example embodiment, the formwork system may further include an insulation support that is configured to couple with the elongate joiner. This can allow for insulation to be installed against one or both of the forms prior to the remaining space being filled with concrete. Preferably, insulation is fitted inside the outer form so that the majority of the thermal mass of the finished wall is inside the insulation, providing significant benefits to the completed building in relation to heating and cooling efficiency.

[0088] In another example embodiment, the formwork system further includes a bottom track configured to abut a substrate and to couple with the first edge of the first panel or an end of the first panel. That is, the panels can be installed in a horizontal or vertical orientation without requiring any different or specific components. Additionally, the bottom track can be used to finish an end of a wall or around window and door openings.

[0089] An example of a permanent formwork for a concrete wall according to the invention will now be described. In this example, the permanent formwork includes an outer form and an inner form, between which concrete is poured. Each of the forms includes a plurality of panels connected by an elongate joiner. The formwork also includes a plurality of brackets, each of which has two coupling portions, so that the bracket can extend between and connect elongate joiners of the outer form and the inner form.

[0090] This permanent formwork may be constructed using any of the components previously described, which may be optional or advantageous aspects of some example embodiments. [0091] An example of a method of constructing a wall, optionally using components described previously, will now be described.

[0092] Firstly, a bottom track may be provided at a location that is to be a bottom of the wall. Next, a first panel can be provided and installed by placing a first edge of the first panel into the bottom track. An elongate joiner can then be provided, fitting it to a second edge of the first panel. A plurality of brackets can next be coupled to the elongate joiner, or may optionally be left until a later stage.

[0093] A second panel can next be provided, placing a first edge of the second panel into the elongate joiner, thereby creating at least part of a first form. Next, reinforcing steel can be arranged adjacent the first form and secured in place. Some of the above steps may now be repeated to begin assembly of a second form in a location adjacent the first form, so that the reinforcing steel is located therebetween. Finally, the brackets of the first form can be coupled with the elongate joiner of the second form, and assembly of the second form continued as necessary.

[0094] A number of other features and/or steps will now be described, which may be optional or advantageous aspects of some example embodiments.

[0095] Typically, the step of installing the bottom track may involve marking out wall comers, tees, window and door openings on the floor and fixing down the bottom track around the steel reinforcing starter bars or any services. Other than the bottom track potentially being of a different design, this step is somewhat similar to what is already known in the art.

[0096] Otherwise, prior art systems are assembled in a substantially different manner. Typically, a three-person team (often chosen to be large, strong men) is required to carry the panel to its designated position, lifting it over the starter bars and holding in position while a brace is fixed to the floor and panel. Subsequent panels are erected as per the panel layout drawings, and each panel must be braced as it is erected. Panels are set plumb and fixed with glue and screws at panel joins.

[0097] In contrast, the present system is much simpler and safer due to the reduced weight of the components, as well as eliminating the gluing process. There are minimal components, and one or two people may be able to easily perform the installation, as the panels may be a fraction of the weight when compared to the prior art systems.

[0098] After the bottom track is down, typically starting at a comer, one or two people place a panel in both sides of the track. Additional panels can be placed along the length of the wall, cutting the last panel to the required length at the end or change of direction.

[0099] An elongate joiner can next be placed on top of each run and brackets knocked into place at 400mm centres along the length. A top hat (strong back) section can be installed vertically to the wall at required centres (nominally 2400mm) and a brace attached. This is about half as many braces as is typically required when compared with existing panel systems.

[0100] The next wall can be started with the off cut of the last run of sheets, installing additional rows to one or both faces of the wall. One face can be taken up to the finished height, secured to the strong back. This allows the wall to remain open on one face to allow the proper installation of reinforcing steel and services and for compliance inspection.

[0101] Reinforcing and services can next be installed, and then an inspection can be done before the wall is completely closed. Finally, the wall is checked for plumb and is then ready for the concrete pour.

[0102] As noted above, one side of the wall may be left open for installation of reinforcing. This is a significant improvement over prior art systems, where every three or four panels reinforcing steel is slid into the open ends of the panels at the available centres and tied where possible. Comers are closed off and open ends of panels and window openings capped and sealed. Panels may need to be opened for the installation or connection of services, and then sheeted over before the concrete pour.

[0103] This means that the ability for engineers to inspect reinforcing in these prior art systems is greatly impeded, if not impossible, creating significant risks for the long-term stmctural integrity of the finished wall. Not only is the inspection difficult, but the increased difficulty of installation means that problems are more likely and the inspection is more important.

[0104] As described above, in the present system the services and reinforcing steel can be installed and tied as each 600mm horizontal layer of wall face is installed, with easy access for structural compliance and inspection. That is, the present system has a clear focus on correct reinforcing installation and visibility. Compliance with structural requirements, that can be easily inspected, resolves the current concerning issues in the prior art for specifiers, engineers and insurers.

[0105] Various other example embodiments of the invention will now be described with specific reference to the figures.

[0106] Referring to Figures 1 to 3, an embodiment of a formwork system 100 is shown that includes an outer form 101 and an inner form 102. Panels 105 are connected by elongate joiners 106, with brackets 108 extending between elongate joiners 106 of the inside form 102 and the outside form 101.

[0107] Referring to Figures 4A and 4B, an alternative example embodiment is shown where the panel 105 and the elongate joiner 106 are supplied pre-assembled, with cladding 110 bonded to a surface and being folded around an edge of the elongate joiner 106. In addition to being bonded, the cladding is further secured in place once the formwork is assembled, as the cladding becomes captured between the panel 105 and the elongate joiner 106. This cladding may be 0.55mm aluminium, but it will be appreciated that other thicknesses and/or materials could alternatively be used.

[0108] Referring to Figures 5 and 6, the formwork 100 is shown in a more advanced stage of assembly. A top hat section 115 has been fixed to the outer form 101 and a brace 116 connected between the substrate and the top hat section 115. The brace 116 supports the outer form 101 while the inner form 102 is being assembled. In this way, reinforcing 120 can be installed prior to the inner form 102 being assembled.

[0109] Referring to Figure 7, an embodiment of the bracket 108 is shown. This bracket has a central section 130 and end sections 131, with slots 132 located between the central section 130 and the end sections 131. The bracket 108, as seen in Figures 1 to 4, couples with the elongate joiners 106 by receiving a portion of the joiners 106 in the slot 132, and the end sections 131 being received in a narrow channel of the joiners 106. This will be described in more detail below. [0110] Figure 8 shows an alternative embodiment of the bracket 108. This embodiment is in the form of a short I-beam, similar to the embodiment of Figure 7 but without any slots. This embodiment is coupled with the joiners 106 by inserting the end sections 131 in the narrow channel of the joiner 106. For this to function correctly, the orientation of this embodiment in use is rotated 90° relative to the embodiment seen in Figures 1 to 4. In this way, the central section 130 will simply rest on a portion of the joiner 106.

[0111] Referring to Figure 9, an embodiment of the elongate joiner 106 is shown. The joiner 106 has an I-shaped cross section comprising a central section 140 and two end sections 141. An additional flange 142 extends from the central section 140 at a location between the end sections 141 but offset so as to be closer to one of the end sections 141. This forms a narrow channel 143 between the flange 142 and the end section 131 to which it is closest, and a wider channel 144 between the flange 142 and the end section 131 to which it is farthest. It can be seen that the cross section is symmetrical, providing for simple installation and no issues with different “handed” components being required.

[0112] Figure 10 illustrates a bottom track 150 that is configured to be located at the substrate at the bottom of the wall. Accordingly, there is a flat base 151, a central portion 152 and an outer flange 153, together forming a wide channel 154 suitable for receiving a panel 105. An additional wide channel 155 is also provided for optionally including a spacer at the base of the wall, as will be described in more detail below. The bottom track 150 is also used around door and window openings, as well as a means for finishing an end of a wall.

[0113] Figures 7 to 10 show dimensions of these particular example embodiments, but it will be appreciated that some or all of these dimensions may change in alternative embodiments in both a relative and absolute sense.

[0114] Figure 11 shows a join between panels 105 in more detail. The elongate joiner 106 can be seen with a panel slotted into each of the wide channels 144, with the inner form and the outer form connected by the bracket 108. The bracket 108 is connected to the joiners 106 by slotting into the narrow channel 143 from above.

[0115] Figure 12 shows the setup at the bottom of the panels 105, where two panels 105 are fitted into base tracks 150. A spacer 160 is fitted between the base tracks, ensuring a correct width of the wall at this base location. This spacer 160 can be a small section of a panel or a separate component. It will typically be provided with holes to allow the reinforcing steel to pass through.

[0116] Figure 13 illustrates an optional embodiment where insulation 170 is fitted adjacent the inner form 102. Insulation brackets 171 are used to support the insulation 170, which are also connected to the elongate j oiners 106 but offset relative to the brackets 108. The insulation may be fitted inside either the outside form 101 or inside form 102, or both, with the remainder of the void being ultimately filled with concrete 175.

[0117] Figures 14A and 14B show an alternative embodiment of the formwork system, in which sheet metal cladding 110 is fitted to the panels 105, which are connected by elongate joiners 106 that are coupled to brackets 108 in a similar way as described above for other embodiments.

[0118] As can be seen in the detail view of Figure 14B, cladding 110 is bonded to an exterior surface of a panel 105 and folded around a lower flange 141ofthe elongate joiner 106. Another panel 105 is engaged with the lower flange 141 to ensure the cladding 110 is secured in place.

[0119] Turning back to Figure 14A, it is noted that this embodiment also includes insulation 170 and concrete 175 in a similar manner as shown in Figure 13 and described above. However, in the example of Figure 14A, a steel reinforcement bar 180 is arranged vertically and extends through the concrete 175.

[0120] Figure 15 shows another alternative embodiment of the formwork system, which is similar to the example of Figures 14A and 14B but without cladding. Further details of the elongate joiners 106 used in this embodiment are shown in Figure 17 and further details of the brackets 108 used in this embodiment are shown in Figures 18A and 18B.

[0121] With regard to Figure 17, the features of this embodiment of the elongate j oiner 106 are similar to those of the example of Figure 9 as described above, and like features have been assigned like reference numbers. However, the narrow channel 143 of the elongate joiner 106 is substantially wider compared to the narrow channel 143 in Figure 9. This change to the narrow channel 143 accommodates flanges 133 that have been added to this embodiment of the bracket 108, as shown in Figures 18A and 18B.

[0122] With regard to Figures 18A and 18B, other than the flanges 133 which extend inwardly from the end sections 131 of the bracket 108, the features of this embodiment of the bracket 108 are similar to those of the example of Figure 7 as described above, and like features have been assigned like reference numbers.

[0123] Turning back to Figure 16, this shows an embodiment of a base assembly for use with the formwork system from Figure 17. The base assembly includes an alternative version of the base tracks 150 into which the panels 105 are fitted at the bottom of the form work assembly as previously shown in Figure 12. The base tracks 150 are similar to those shown in Figure 10 and described above, although these include additional inner flanges so as to define a channel for engaging with flanges 133 of the brackets 108. Accordingly, brackets 108 can also couple with the base tracks 150 in a similar manner as they engage with the elongate joiners 106.

[0124] In the foregoing description of preferred embodiments, specific terminology has been resorted to for the sake of clarity. However, the invention is not intended to be limited to the specific terms so selected, and it is to be understood that each specific term includes all technical equivalents which operate in a similar manner to accomplish a similar technical purpose. Terms such as “front” and “rear”, “inner” and “outer”, “above” and “below” and the like are used as words of convenience to provide reference points and are not to be construed as limiting terms

[0125] 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 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. As used herein and unless otherwise stated, the term “approximately” means ±20%.

[0126] Persons skilled in the art will appreciate that numerous variations and modifications will become apparent. All such variations and modifications which become apparent to persons skilled in the art, should be considered to fall within the spirit and scope that the invention broadly appearing before described.