AU782290B2 - Transparent concrete formwork - Google Patents

Description

TRANSPARENT CONCRETE FORMWORK FIELD OF THE INVENTION This invention relates to improved formwork, which is a temporary mould in which concrete, other settable materials, rammed earth and the like can be placed. The invention will be described with reference to concrete formwork, but other uses of the formwork are envisaged.

BACKGROUND ART The function of formwork is to hold fluid concrete into the desired S7.i shape, to support fresh concrete until it is strong enough to be self-supporting, and to support temporary loading such as runways and machinery used to place the concrete.

Formwork should be simple to erect and dismantle. Only the minimum number of fasteners should be used. The formwork must remain straight and rigid when concrete is poured and therefore adequate bracing is essential to prevent movement caused by vibrators, concrete pumps and other machinery. The formwork should be tight to prevent loss of "fines". Any leaks can produce honeycombing or ridges on the finished concrete. Formwork should also be constructed such that maximum re-use is possible.

S: Formwork panels are made of wood boards, steel sheets, hard .i 20 boards or resin bonded plywood. In order to allow the formwork to be made portable, the boards or sheets are relatively thin and therefore must be supported.

Formwork junctions must be able to support quite large forces and stresses, and the formwork must not warp, bow, or leak. Angled formwork, that is where adjacent formwork panels meet at an angle, require special consideration, and to date, complicated and unwieldy support devices are used to clamp formwork panels together at an angle.

With multi storey concrete buildings, formwork is used to allow a concrete floor to be poured. The formwork must be adequately supported by hundreds or more props. The amount of formwork and supports results in a marked lowering of light levels which results in unsafe work areas. Temporary electric lighting can be used but this creates additional hazards due to loose lying cables, and having high voltage electric lights.

A further disadvantage with current formwork is that it must be removed to allow the concrete set to be inspected. Naturally, the concrete must be sufficiently set before the formwork can be removed, and if a subsequent inspection finds an unsatisfactory set, the concrete must be broken up and removed. Unsatisfactory sets can occur if voids form or concrete does not flow properly about reinforcement. To minimise this, vibrators are currently in use but even vibrators are not completely successful in ensuring a good set.

Formwork is also subjected to abrasion due to the very abrasive action of concrete both physically and chemically. Formwork panels therefore are usually quickly scratched, scoured and abraded on their surface.

oeool: Formwork must also be able to stay straight or in the desired shape and must not deform during a heavy cement pour.

Attempts have been made in order to allow inspection of the concrete through the formwork. For instance, while it may be theoretically possible to manufacture a transparent formwork out of resin, resin is generally not very strong, and these panels have to be extremely thick and therefore heavy and clumsy in order to support a concrete pour. The panels, while being so thick, do not find practical use when used with other conventional formwork.

Attempts could be made to reinforce formwork while still providing viewing ports or openings. For instance, strong thick steel plates could be used as formwork, and holes could be drilled through these plates in order to provide inspection portholes. The holes could be made sufficiently small such that only a thin clear plastic layer is required over the holes. However, formwork formed from steel plates is also cumbersome, heavy and subject to rust and corrosion. The fairly small viewing portholes are difficult to see through and insufficient light passes through the holes to enable the poured concrete to be properly inspected.

Attempts could be made to make clear formwork by framing plexiglass within a surrounding steel frame. However, the plexiglass pane could not be made too large, as it will deform during a concrete pour. This arrangement would severely limit the versatility of the formwork. The surrounding steel frame could be flush on one side but will need to extend outwardly from the plexiglass on the other side. The formwork would therefore not be reversible as only one side can face the concrete pour. Making the surround frame narrower in order to be flush on both sides would result in the formwork bending unless the formwork is made sufficiently small in which case it would lack versatility.

Attempts could be made to reinforce clear panels with steel rods or grids. However, these panels may not meet with success as steel has a large coefficient of expansion and delamination or debonding between the steel and the remainder of the panel could occur over time. This may not be immediately 10 apparent, and can result in premature fatigue or total failure of the formwork panel during a concrete pour which can create a hazardous situation.

In summary, current formwork is either non-transparent, or if attempts are made to provide portholes or transparent sections, it is found that the formwork is too heavy and unwieldy to be portable enough for use on sites, or very expensive because of the amount of resin required to manufacture a practical thickness, and unpredictable delamination can occur between the reinforcement and the resin.

OBJECT OF THE INVENTION The present invention has developed improved formwork which is 20 transparent and which can be reused many times.

It is an object of the invention to provide formwork which may overcome the abovementioned disadvantages or provide the public with a useful or commercial choice.

In one form, the invention resides in formwork comprising at least one formwork panel, the panel being sufficiently transparent to allow concrete to be viewed through the panel.

In a second form, the invention resides in a formwork panel assembly comprising a lamination of a plurality of transparent panel members.

In a third form, the invention resides in a method of forming a transparent formwork panel assembly of the type comprising a plurality of transparent panel members bonded together, the method comprising the steps of roughening the surfaces of at least of the panel members to be bonded which reduces the clarity of the panel members, applying a layer of transparent bonding agent to at least one of the roughened surfaces, and placing the panel members together to form the assembly, the bonding agent bonding the panel members together and causing the roughened surfaces to become transparent.

The method may preferably further include the step of allowing the bonding agent to rest or cure for a predetermined time. After curing for a predetermined time, the laminated formwork panel may preferably be moved to a pressure applying means. The pressure applying means may be a surface upon which the laminated formwork panel is placed, and a weight placed upon the laminated panel.

The pressure applying means may preferably be a planar or a shaped mould. The shaped mould may preferably include a first shaped member and a second shaped member. The shaped mould may also preferably *comprise a first shaped member and a single second member, capable of 15 conforming to the shape of the first shaped member. The second member may preferably be a shaped sheet of metal which conforms to the shape of the first shaped member.

The pressure applying means will preferably take the form of a first shaped member, and a plurality of second members, and joined by linking 20 means. The first shaped member will preferably be a substantially plate like member of any shape and configuration which may be required for cement formwork. The first shaped member may preferably have a straight longitudinal cross-section with an arcuate transverse cross-section.

The second members are preferably made of metal, and the linking means is preferably take attached to the longitudinal ends of the second members.

In use, the pressure applying means suitably allows the transparent panel members to conform to a predetermined shape which is used in cement formwork. The pressure applying means preferably applies pressure until the bonding agent is fully cured. The bonding agent to then maintains the laminated transparent panel members in their newly formed shape.

It will be appreciated that the pressure applying means may be manual or automatic. It may also be horizontal or vertical and made of any material suitable for the application of a pressure force.

The method of laminating the transparent panel members may also further comprise the step of including an internal grid or mesh between the first and second transparent panel members.

In a fourth form, the invention resides in a reinforced formwork panel assembly comprising an internal non-transparent grid or mesh having a expansion coefficient sandwiched between and bonded to a pair of o. transparent panel members.

In a fifth form, the invention resides in a reinforced formwork panel S: comprising an internal reinforcing grid or mesh optionally having a low expansion coefficient and embedded in a transparent material.

In a six form of the invention, the transparent panel has a working face with a removable clear layer on the working face.

By working face is meant the side or face of the panel which usually contacts the concrete, and is therefore subjected to abrasion.

The removable clear layer functions to protect the working face against abrasion, thereby keeping the panel sufficiently transparent for as long •as possible. This layer can be a use once layer or a layer which can be reused a 20 number of times.

The layer can be sheet material, a paint on or spray on or otherwise applicable hardenable liquid or gel, or a "sacrificial" plate like member which can be attached to the working surface.

Suitable layers can comprise clear plastic flexible sheets or films, rigid or substantially rigid plastic sheets. It is possible to apply the layer only to the working face, or to cover or wrap both sides of the panel or even the entire panel. A thin glass sheet is also envisaged as suitable with formwork which does not bow or deform during the pour. If desired, a plurality of layers can be attached to the panel, such that removal of an upper scuffed or abraded layer reveals a lower fresh undamaged layer The thickness of the layer and the toughness of the layer should be sufficient to protect the transparent panel for at least one use and possible for multiple uses.

By having the formwork transparent, improved lighting conditions are realised with multi storey buildings, and visual inspection of the concrete pour is much easier.

By having the working face protected by a clear layer, concrete does not directly contact the panel and does not abrade the panel itself. The panel can then be used many times.

The transparent panel members and/or the transparent material may comprise polymers such as polyester, polyethylene, polypropylene, ABS resin, vinyl chlorides, PMMA, other methycralates, nylons, polycarbonates, crystalline polyolyfin such as high density polyethylene, polymers and copolymers thereof and plexiglass. Other transparent materials will be apparent to a person skilled in the art.

If the formwork panel comprises a lamination of a plurality of transparent panel members, the members may be formed from the same or different material. The panel members may have the same or different thickness, and may have the same or different properties of density, flexibility, rigidity, impact resistance and the like, with the proviso that the entire panel assembly is suitable for its intended use. Suitably, the panel members are 20 formed from a high impact acrylic or similar material.

The transparent panel members so laminated may preferably also be planar or shaped along a transverse cross-section. Shaped transparent panel members are generally formed with as being rectangular when viewed in elevation, and shaped when viewed in plan. The shape may preferably be circular, arched, arcuate, corrugated, domed, parabolic, or indeed any other usable or required shape.

If desired, the panel assembly may be reinforced. For instance, the panel assembly may include a reinforcing layer of a material such as fibreglass strands or matting or carbon fibres and the like which suitably become transparent when treated or bonded with resins. Thus, the panel assembly may include a number of transparent panel members and one or more intermediate layers or reinforcement.

The term "transparent" defines the ability of a person to see through the transparent area and to enable the person to at least partially inspect the poured concrete. That is, the term "transparent" is not meant to be limited to entirely transparent but may include a level of transparency which will enable the inspection to be carried out.

The panel assembly can be formed by bonding the panel members together. To minimise delamination, the panel members may initially be etched or roughened up either mechanically or chemically or by other means S'in order to allow panel members to be strongly bonded together.

The bonding agent is chosen to be transparent when cured. The bonding agent is preferably a thermoplastic resin. It may also preferably comprise a resin of any type which is clear when cured.

During the etching or roughening process, the surface of the panel "members become cloudy or even opaque, but upon addition of the bonding layer, transparency is returned to the panel members.

ts In a seventh form, the panel assembly is formed from a plurality of transparent panel members where the panel members are bonded to each other in discrete areas. These areas or zones may extend around the periphery of the panel assembly and/or inside the peripheral area. This arrangement may be 20 suitable if the bonding agent is not transparent enough therefore by applying the bonding agent in only discrete zones, transparent regions are still retained.

In the fourth form of the invention, the formwork panel assembly is reinforced using an internal grid or mesh which has a low expansion coefficient sandwiched between and bonded to a pair of transparent panel members. The panel members may be as described above. The grid or mesh may be formed from metal having a low expansion coefficient and it is found that aluminium is a suitable member. The aluminium is of course non-transparent but it is found that the grid or mesh can have fairly large open areas which provides ample transparency to the panel assembly. It is preferred that the grid or mesh is an aluminium mesh which may be extruded or stamped. The mesh preferably has zones of different widths the reason of which will become apparent below.

By having a grid or mesh with a low expansion coefficient, it is 8 found that the risk of delamination is greatly reduced or eliminated. Thus, the transparent panels can be bonded to the aluminium mesh with reduced risk of delamination occurring with catastrophic failure of the panel. The panel members may be bonded to the grid or mesh using a bonding agent. In one form, the bonding agent entirely fills the void between the panel members and in which the mesh is positioned. By having the mesh of irregular width, improved bonding between the panel member, the mesh and the bonding agent occurs ".resulting in a strong rigid yet lightweight panel assembly.

9*i In an eighth form, the panel members may be bonded to the mesh adjacent the periphery of the panel assembly with the remainder of the internal t area of the panel assembly being a void. The void can be filled with dry air to minimise condensation.

In a ninth form, the invention resides in a reinforced panel comprising an internal reinforcing grid or mesh which may be as described *15 above which is embedded in a transparent material such as a resin. In this form of the invention, the mesh or grid panel is placed in a mould or surround frame and a settable resin is poured about the mesh or grid and subsequently set. It is again preferred that the mesh or grid is of irregular or different widths to facilitate 9 bonding of the resin to the mesh or grid.

20 The reinforcement may include glass fibres, alumina fibres, woven or non-woven pads, cloths, webbing and the like. The polymer material may include additives such as stabilisers, colourants, fillers and the like with the proviso that the additives do not reduce the transparency of the resultant panel member to an undesirable level.

BRIEF DESCRIPTION OF THE DRAWINGS Various embodiment of the invention will be described with reference to the following drawings, in which: Figure 1 is a view of formwork according to the sixth embodiment of the invention.

Figure 2 shows formwork according to the second embodiment of the invention, showing two laminated panel assemblies and the resultant pore of concrete as well as the position of concrete reinforcing rods between the assemblies.

Figure 3 shows the second embodiment of the invention as a reinforced panel assembly.

Figure 4 shows the ninth embodiment of the invention wherein the panel members are bonded to the internal reinforcing mesh adjacent to the periphery of the panel assembly with the remainder of the internal area being free from bonding resin with a greater optical transparency.

Figure 5 shows a shaped, laminated formwork panel according to :the fourth embodiment of the invention wherein the panel is curved and the reinforcing mesh can clearly be seen.

Figure 6 shows a perspective view of the first shaped member of fee*.: the fourth embodiment of the invention.

Figure 7 shows a perspective view of the first shaped member of the fourth embodiment of the invention with the panel assembly in place.

15 Figure 8 shows a perspective view of the first shaped member of the fourth embodiment of the invention with a panel assembly in place and showing the preferred form of the plurality of second members joined by linking means.

•C Figure 9 is an end elevation of the assembly of Figure 8 showing 20 the curved transverse section of the panel assembly.

Figure 10 and shows a side elevation of the assembly shown in Figure 9.

BEST MODE Referring to Figure 1, there is shown a clear formwork panel Panel 30 is made from strong clear plastic and can have various lengths and widths to suit. The thickness of the panel can also vary as long as the transparency of the panel is not reduced to the point where it is no longer see through.

Panel 30 has a peel off front layer 31 and a peel off rear layer 32.

Layer 31 is against the concrete while layer 32 is against the rear face of the panel. The peel off layers are manufactured from plastic. The layers have a tack adhesive to stick the layers to the panel in a removable manner. Alternatively, static friction may be sufficient to keep the layers attached to the panel. Of course, the layer can also comprise a bag or envelope which entirely surrounds the panel. The layer must be tough enough to protect the panel during the concrete pour, and various plastics can be used. The rear layer protects the rear face of the panel against scuffing by workmen when the panels are fitted, removed or transported.

In Figure 1, a concrete pour has been completed, and, as is :normal, a vibrator 34 is pushed into the wet concrete to ensure that the concrete 1 flows into all the crevices and around reinforcement. However the vibrator is not very efficient, and in Figure 1, a void 35 remains undetected.

Previously, when the wooden formwork was removed, and the void found by an inspector, it was necessary to bog up the void or redo the concrete pour.

With the present invention, any irregularities in the pour can be better viewed and corrected before the concrete sets hard.

Figure 2 shows formwork according to another embodiment of the invention. In this figure, the formwork consists of two spaced apart panel assemblies 36, 37. Each panel assembly is formed from a lamination of two high impact transparent acrylic sheets. The sheets are bonded together by initially roughening the surfaces of each sheet and then applying a bonding agent to the roughened surface and clamping the two sheets together until the bonding agent cures to form a strong rigid clear laminated panel assembly. In Figure 2, the two panel assemblies are shown as formwork and illustrate how a resultant concrete pour 38 can be inspected as can the position of the concrete reinforcing rods 39.

Figure 3 illustrates a further embodiment of the invention. In this embodiment, there is illustrated a reinforced panel assembly. The panel assembly is formed from two clear panel members 40, 41 which sandwich an aluminium mesh 42. Initially, a first panel is laid in a mould and mesh 42 is placed on the first panel. Thereafter, a transparent bonding agent or resin is poured over the mesh to fill all the cavities. The second panel member is then placed on top of the mesh making sure that all air pockets are removed. The bonding agent is then cured to form the panel assembly. By having the aluminium mesh which has a low expansion coefficient, there is reduced likelihood of delamination occurring. The mesh is preferably of irregular thickness which means that the bonding agent can flow over the mesh from one panel to the other panel to provide an extremely strong bonded arrangement.

Figure 4 illustrates a variation of Figure 3 which again consists of two panel members 40, 41 and an internal aluminium grid or mesh 42. In this .o variation, the bonding agent or resin is poured only around the peripheral area 43 of the panel assembly leaving the central area 44 free from bonding resin and 10 therefore having a greater optical transparency. In this embodiment, it is *I preferred that the mesh has an irregular thickness where the bonding agent is applied to again securely lock the two panels together and to the mesh.

Figure 5 illustrates a shaped formwork panel 45 manufactured according to the third and fourth embodiments of the invention.

In this embodiment, there is illustrated a shaped, reinforced panel assembly 45. The shaped panel assembly 45 is formed from two clear panel members which sandwich an aluminium mesh 42. Initially, a first panel is laid in a flat or planar mould, and reinforcing mesh 49 is placed on the first panel.

o.o. Thereafter, a transparent bonding agent or resin is poured over the mesh 49 to fill all the cavities. The second panel member is then placed on top of the mesh 49 making sure that all air pockets are removed. The bonding agent is then cured to form a flat panel assembly.

After a predetermined during time, the flat assembly comprising the two clear panel members, the bonding agent and the sandwiched mesh 49, is moved from the flat mould to a curved mould. The predetermined during time differs for different resin is not is selected to minimise the stress created within the panel assembly, and therefore maintain the adhesive qualities of the resin and the strength of the overall panel assembly.

By using the aluminium mesh 42, which has a low expansion coefficient, there is reduced likelihood of delamination occurring. The mesh is preferably of irregular thickness which means that the bonding agent can flow over the mesh from one panel to the other panel to provide an extremely strong bonded arrangement.

The curved mould comprises a first shaped member 46 shown in Figure 6. This member is strong enough to support the weight of the combined assembly and the second members 50 as shown in Figures 8-10.

The first shaped member 46 defines of the shape of the formwork panel 45 to be manufactured. As can be seen from Figures 6-10, the first shaped member 46 has a straight longitudinal cross-section 48 with an arcuate transverse cross-section 47. However, it will be appreciated that the first shaped member 46 may be of any shape required for the concrete pour. The first 10 shaped member 46 is shown in Figure 7, with a panel assembly in place.

The curved mould also comprises a plurality of second members the purpose of which is to provide pressure on the still curing formwork panel assembly 45, to ensure the assembly takes the shape of the mould.

As can be seen in Figure 8, there is a plurality of second members 50 placed over the panel assembly 45, the plurality of second members joined by linking means 51. The linking means 51 shown in that Figure is a tape.

The linking means 51 allows the second members 50 to be rolled up for easy storage and transport.

Each second member 50 is an elongate plate member. When in place, they give an even distribution of weight over the curing panel assembly.

The use of the plurality of second members 50 joined by linking means 51 also allows the same device to be used in the formation of shapes with smaller radii curves or corrugated shapes.

It was found by the inventor, that this make up of a plurality of second members 50 joined by linking means 51 is the most effective pressure applying means, allowing the formation of a diverse range of shapes of formwork panel assemblies, including planar assemblies.

It should be appreciated that various other changes or modifications are envisaged without departing form the spirit and scope of the invention. The purpose of the invention is to create a transparent formwork, shutter or panel that allows viewing of the prepared area but which is not extremely heavy, or bulky, or is otherwise unsuitable for use in the formwork 13 industry. The invention is meant to include various types of transparent material such as resins or plastics either alone or in combination to create a transparent membrane to form a face for the surface of the finished concrete wall, ceiling or any structure. In the preferred form of the invention where reinforcing is required, transparent materials are used to the maximum and non-transparent materials are used to the minimum wherever possible.

DATED this 28 t h day of February 2002 CONCRETE FORM HIRE PTY LTD (ACN 075 692 670) 10 By their Patent Attorneys CULLEN CO.

Claims (41)

1. A transparent concrete formwork assembly comprising a plurality of formwork panel members laminated together to form a panel, and a non- transparent grid or mesh sandwiched between at least two of the transparent panel members, wherein the panel is sufficiently transparent to allow viewing through the panel.

2. The assembly of claim 1, wherein the lamination of the transparent panel members is achieved using a bonding agent which is transparent when cured to bond the plurality of transparent panel members together.

3. The assembly of claim 2, wherein the bonding agent comprises a resin.

4. The assembly of either claim 2 or 3, wherein the bonding agent S: comprises a thermoplastic.

5. The assembly according to any one of claims 2-4, wherein the o 15 bonding agent entirely fills any void between the panel members.

6. The assembly of any one of the preceding claims, wherein the non- go transparent grid or mesh has a low expansion coefficient.

7. The assembly of any one of the preceding claims, wherein the mesh is stamped or extruded. 20

8. The assembly of any one of the preceding claims, wherein the mesh is aluminium.

The assembly according to any one of the preceding claims, wherein the non transparent grid or mesh is bonded to at least one transparent panel member.

10. The assembly according to any one of the preceding claims, wherein a transparent panel member has at least one surface which usually contacts 0 the concrete, said at least one surface having a clear removable layer.

11. The assembly of claim 10, wherein the removable clear layer is removed after every use.

12. The assembly of either claim 10 or 11, wherein the clear removable layer is a clear plastic flexible sheet or film.

13. The assembly of any one of claims 10 to 12, wherein the at least one surface of the transparent panel member has more than one clear removable layer.

14. The assembly of any one of the preceding claims, wherein the plurality of transparent panel members are formed of the same material.

The assembly of any one of the preceding claims, wherein the plurality of transparent panel members have similar dimensions.

16. The assembly of any one of the preceding claims, wherein the plurality of transparent panel members possess similar properties.

17. The assembly according to any one of the preceding claims where the transparent panel members are planar.

18. The assembly according to any one of claims 1-17, wherein the panel has at least one surface which usually contacts the concrete, said at least one surface having a shaped configuration. *oll

19. The assembly according to claim 18, wherein the at least one "surface has a circular, arched, arcuate, corrugated, domed or parabolic shape. •l

20. The assembly according to any one of the preceding claims, wherein the panel assembly is reinforced using at least one reinforcing layer.

21. The assembly according to claim 20 wherein the reinforcing layer may include glass fibres, alumina fibres, woven or non-woven pads, cloths, 2 webbing, matting or carbon fibre and the like, which become transparent when treated all bonded with a bonding agent.

22. The assembly according to any one of the preceding claims, wherein the plurality of transparent panel members are bonded to each other in discreet areas.

23. The assembly according to claim 22, wherein the discreet area extends around the periphery of the panel assembly creating a void space in the internal area of the panel assembly.

24. The assembly according to claim 23, wherein the void space is filled with dry air.

A transparent concrete formwork assembly comprising at least one transparent panel member and an internal reinforcing grid or mesh having a low expansion coefficient, embedded in a transparent material, the at least one transparent panel and the transparent material laminated together to form a transparent panel member. 16

26. The transparent concrete formwork assembly according to claim wherein the transparent material is a curable resin.

27. The transparent concrete formwork assembly according to either claim 25 or 26, wherein the transparent material is a thermoplastic.

28. The assembly according to any one of the preceding claims, wherein the transparent panel members comprises polymers such as polyester, polyethylene, polypropylene, ABS resin, vinyl chlorides, PMMA, other methycralates, nylons, polycarbonates, crystalline polyolefin such as high density polyethylene, polymers and copolymers thereof, plexiglass or other transparent material.

29. The assembly according to claim 28, wherein the polymer material includes additives such as stabilises, tolerance, fillers and the like which do not produce the transparency of the resultant panel member to and undesirable level. 15

30. A method of forming a transparent formwork panel assembly of the type comprising a plurality of transparent panel members bonded together, the 99999* method comprising the steps of roughening the surfaces of at least one of the panel members to the bonded which reduces the clarity of the at least one panel member, applying a layer of transparent bonding agent to at least one of the roughening surfaces, placing a non transparent grid or mesh between the :0: panel members to be bonded together and placing the panel members together to form the assembly, the bonding agent bonding the panel members together and causing the rough and surfaces to become transparent.

31. The method according to claim 30, further comprising step of allowing the bonding agent to rest or cure for a predetermined time.

32. The method according to claim 31, further comprising step of moving the laminated formwork panel after the predetermined time has collapsed, to a pressure applying means.

33. The method according to claim 32 where the pressure applying means comprises a surface upon which the laminated formwork panel is placed, and means for applying pressure to the laminated panel.

34. The method according to claim 33, wherein the pressure applying means is a mould having a first member and at least one second member, the 17 first member adapted to support the laminated formwork panel, and the at least one second member adapted to provide pressure on the laminated formwork panel.

The method according to claim 33, the means for applying pressure to the laminated panel is a plurality of substantially elongate platelike members, placed on the laminated formwork panel.

36. The method according to claim 35, wherein each of the plurality of substantially elongate plate like members are joined at their longitudinal ends, using linking means.

37. The method according to claim 36 wherein the linking means is a resilient band.

38. The method according to claim 34, wherein the first member and the *o at least one second member are manufactured from metal or plastic.

39. The method according to claim 34, wherein the first member has a go 15 shaped cross section, adapted to manufacture laminated formwork panels which are not planar.

The method according to any one of claims 30 to 39, wherein the laminated formwork panels are held in a predetermined position until the bonding agent is fully cured.

41. A transparent concrete formwork assembly substantially as described with reference to the attached drawings. DATED this 24 m day of May 2005 Concrete Form Hire Pty Ltd By their Patent Attorneys CULLEN CO.