FORMWORK APPARATUS AND METHOD OF ERECTING FORMWORK APPARATUS

FIELD OF THE INVENTION

The present invention relates to a formwork apparatus typically for use in the construction field, for example in relation to construction methods utilising a pourabie substance such as concrete. The present invention also relates to a method for erecting formwork apparatus,

BACKGROUND

The discussion of the prior art within this specification is not, and should not be taken as, an admission of the extent of common general knowledge in the tield of the invention. Rather, the discussion of the prior art is provided merely to assist the addressee to understand the invention and is included without prejudice.

Existing techniques for in-situ construction of concrete structures typically require erection of formwork itom generic materials such as plywood. This can be labour intensive, costly and wasteful of fonnwork materials. Additionally, input from skilled tradespeople is typically required. A particular problem experienced with some prior art fonnwork techniques is the initial positioning of the fonnwork and subsequently maintaining it in the desired configuration during both assembly and the concrete pouring steps,

SUMMARY OF THE INVENTION

According to a first aspect of the invention there is provided a fonnwork apparatus including: a panel defining an interior side for containment of a pourabie substance and an exterior side having a peripheral region and a central region; and a brace being coπnectable to said peripheral and central regions such that, in use, a first force having a component directed toward said interior side is applied by the brace to the panel within said central region and a second force having a component directed toward said exterior side is applied by the brace to the panel within said peripheral region.

Preferably a magnitude of the first force and a magnitude of the second force are selectively adjustable.

One preferred embodiment of the brace includes at least one tension member attached to the panel within the peripheral region and at least one compression member attached to the panel within the central region. Preferably the tension member has a selectively adjustable tension. A preferred embodiment of the tension member includes at least one rod in threaded engagement with a hollow body such that rotation of the body relative to the rod provides the selectively adjustable tension. More particularly, the tension member is preferably a turnbuckle.

In a preferred embodiment the peripheral region defines an upper periphery and a lower periphery. In such a preferred embodiment, the brace includes a first tension member extending intermediate the upper periphery and a compression member disposed within said central region. In this preferred embodiment the brace further includes a second tension member extending intermediate the lower periphery and the compression member. Preferably the compression member is U-shaped so as to define first and second ends adapted for connection within the central region. Also preferably the compression member has first and second connection points for connection of the first and second tension members respectively. In this preferred embodiment the first and second connection points are disposed on the compression member remote from the first and second ends. Preferably the compression member defines a plane which, in use, is disposed substantially at right angles to an elongate axis of the panel.

Preferably two of the panels are arranged so as to define a space intermediate their respective interior sides for containment of a pourable substance such that the space has a height of greater than 1.5 meters and wherein no supports extend through the space, thereby allowing the apparatus to function as a single sided shutter.

According to a second aspect of the invention there is provided a formwork apparatus including:

first and second panels, each panel defining a panel edge having a plurality of panel apertures disposed adjacent said panel edge such that, in use, placement of the two panel edges adjacent each other defines a substantially constant separation distance between respective panel apertures on the first and second panels; a connection plate having first and second connection plate apertures being separated by said constant separation distance to allow for alignment of said connection plate such that the first connection plate aperture is aligned with a selected one of the apertures on the first panel and such that the second connection plate aperture is aligned with a selected one of the apertures on the second panel; and a first fastener being insertable through the first connection plate aperture and through said selected one of the apertures on the first panel so as to affix the connection plate to the first panel; and a second fastener being insertable through the second connection plate aperture and through said selected one of the apertures on the second panel so as to affix the connection plate to the second panel, thereby effectively affixing the first panel to the second panel via the connecting plate.

Preferably each of the panel apertures and each of the connection plate apertures have a substantially identical elongate shape, which in the preferred embodiment is substantially rectangular.

Preferred embodiments of the first and second fixing means each include: a wedge; a shaft having an elongate head shaped so as to correspond with the elongate shape of the panel apertures and the connection plate apertures, the shaft further including a slot for receiving the wedge; and a collar defining an aperture for receiving the shaft, the collar further defining a pair of projections. Preferably each of the projections have tapered ends.

In a preferred embodiment the panel apertures are disposed at substantially 45° relative to an elongate axis of the panel.

Preferably, the substantially constant separation distance is constant to within tolerances of equal to, or less than, approximately +2 mm.

In accordance with a third aspect of the invention there is provided a method of erecting formwork apparatus including the steps of: providing first and second panels, each panel defining a panel edge having a plurality of panel apertures disposed adjacent said panel edge; positioning the first and second panels such that their respective panel edges are adjacent each other; providing a connection plate having first and second connection plate apertures; aligning said connection plate such that the first connection plate aperture is aligned with a selected one of the apertures on the first panel and such that the second connection plate aperture is aligned with a selected one of the apertures on the second panel; inserting a first fastener through the first connection plate aperture and through said selected one of the apertures on the first panel so as to affix the connection plate to the first panel; and inserting a second fastener through the second connection plate aperture and through said selected one of the apertures on the second panel so as to affix the connection plate to the second panel, thereby effectively affixing the first panel to the second panel via the connection plate.

Preferably each of said panel apertures and each of said connection plate apertures have a substantially identical elongate shape defining a major aperture axis and a minor aperture axis.

Preferably the step of "inserting a first fastener through the first connection plate aperture and through said selected one of the apertures on the first panel so as to affix the connection plate to the first panel" includes the steps of: aligning the major head axis with the major aperture axis of the first connection plate aperture;

inserting the head through the first connection plate aperture and through a selected one of the apertures on the first panel; rotating the shaft such that the major head axis is substantially aligned with the minor aperture axis of the selected one of the panel apertures, thereby captively retaining the shaft within the selected one of the panel apertures; inserting the collar onto the shaft such that the projections are aligned with the minor head axis, and inserting the wedge into the slot so as to drive the projections into the major aperture axis of the connection plate aperture, thereby resisting rotation of the fastener relative to the panel and clamping the head against the selected one of the panel apertures.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 is a perspective view of a preferred embodiment of the formwork apparatus, showing four interconnected panels, with braces applied to some of those panels;

Figure 2 is a perspective view of the preferred embodiment showing sections A to I that are depicted in greater detail in figures 3 to 11;

Figure 3 is a detailed depiction of section A from figure 2;

Figure 4 is a detailed depiction of section B from figure 2;

Figure 5 is a detailed depiction of section C from figure 2;

Figure 6 is a detailed depiction of section D from figure 2;

Figure 7 is a detailed depiction of section E from figure 2;

Figure 8 is a detailed depiction of section F from figure 2;

Figure 9 is a detailed depiction of section G from figure 2;

Figure 10 is a detailed depiction of section H from figure 2;

Figure 11 is a detailed depiction of section I from figure 2;

Figure 12 is a perspective view of the preferred embodiment as viewed from a side opposite to the viewing side of figure 1;

Figure 13 is a perspective view of the preferred embodiment showing sections A to C that are depicted in greater detail in figures 14 to 16;

Figure 14 is a detailed depiction of section A from figure 13;

Figure 15 is a detailed depiction of section B from figure 13;

Figure 16 is a detailed depiction of section C from figure 13;

Figure 17 is a side view of a panel;

Figure 18 is a side view of a beam showing sections D and M that are depicted in greater detail in figures 19 and 20;

Figure 19 is a detailed depiction of section D from figure 18;

Figure 20 is a detailed depiction of section M from figure 18;

Figure 21 is a larger scale detailed depiction of section E from figure 19;

Figure 22 is a larger scale detailed depiction of section N from figure 20;

Figure 23 is a perspective view of a panel showing sections A, B and C that are depicted in greater detail in figures 24 to 26;

Figure 24 is a detailed depiction of section A from figure 23;

Figure 25 is a detailed depiction of section B from figure 23;

Figure 26 is a detailed depiction of section C from figure 23;

Figure 27 is a perspective view of a compression member arm;

Figure 28 is a perspective view of a lifting lug;

Figure 29 is a perspective view of a shaft from a plate-first fastener;

Figure 30 is a perspective view of a shaft from a straight-plates fastener;

Figure 31 is a perspective view of a shaft from a plate-last fastener;

Figure 32 is a perspective view of a top bridging fastener;

Figure 33 is a perspective view of a pair of adjacent beams as connected by a connection plate and a pair of fasteners;

Figure 34 is a perspective view of a fastener;

Figure 35 is a perspective view of a disassembled fastener;

Figure 36 is a perspective view of a beam fastened to a connection plate via a plate -first fastener;

Figure 37 is a perspective view of a beam fastened to a connection plate via a plate -last fastener;

Figure 38 is a perspective view of a bridge connected via a straight -plate fastener and a plate-last fastener;

Figure 39 is a perspective view of a plate-last fastener as utilised in figure 38; and

Figure 40 is a perspective view of a straight-plate fastener as utilised in figure 38.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to the drawings, the formwork apparatus 1 includes a panel 2 defining an interior side 3 for containment of a pourable substance, for example concrete 4. In many applications, two panels are placed opposite each other and concrete 4 is poured into the space between the two panels . The panel 2 also defines an exterior side 5 having a peripheral region 6 and a central region 7. The panel 2, along with the majority of the other pieces that collectively constitute the preferred embodiment, is manufactured from a strong workable material such as steel.

The formwork apparatus 1 also includes a brace 8 being connectable to the peripheral and central regions 6 and 7 such that, in use, a first force having a component 10 directed toward the interior side 3 is applied by the brace 8 to the panel 2 within the central region 7, as best shown in figures 4 and 5. The brace 8 also applies a second force having a component 12 directed toward the exterior side 5 of the panel 2 within the peripheral region 6, as best shown in figures 3 and 6.

The magnitude of the first force and the magnitude of the second force are selectively adjustable. This allows a user to selectively apply an appropriate amount of force to the panel 2 to counter any bulging of the panel 2 due to the weight of the pourable substance being contained thereby. This, in turn, allows the panels 2 to be lighter than would be the case if they had to constrain the concrete 4 without the assistance of the brace 8. It will be appreciated that decreasing the weight of each panel 2 is highly desirable as lighter panels are easier to transport and erect.

One preferred embodiment of the brace (not illustrated) includes one tension member having a selectively adjustable tension attached to the upper peripheral region of the panel and one compression member attached to the panel within the central region. This embodiment of the brace is also rotatably connected to the lower peripheral

region of the panel. Hence, this embodiment of the brace acts as a lever, with the lower connection point acting as a fulcrum.

In the embodiment illustrated in figures 1 to 11, the peripheral regions 6 of each of the panels 2 define an upper periphery 13 and a lower periphery 14. The brace 8 includes a first tension member 15, which extends between the upper periphery 13 and a compression member 16, which is disposed within the central region 7. The brace 8 further includes a second tension member 17 extending between the lower periphery 14 and the compression member 16.

In the illustrated preferred embodiment, each of the tension members 15 and 17 are turnbuckles. They each include a pair of rods 18 and 19 in threaded engagement with opposite ends of a hollow body 20. The body 20 includes a pair of integral hexagonal faces, allowing a user to use a wrench or similar tool to rotate the body 20. Rotation of the body 20 relative to the rods 18 and 19 forces the rods either longitudinally away from, or longitudinally toward, the hollow body 20. More particularly, rod 18 is threadedly engaged with the body 20 via a right hand screw thread, whereas rod 19 is threadedly engaged with the body 20 via a left hand screw thread. Hence, when the body 20 is rotated in a clockwise rotational direction the rods 18 and 19 are forced inward, thereby increasing the amount of tension exerted by the turnbuckle. Alternatively, when the body 20 is rotated in an anticlockwise rotational direction the rods 18 and 19 are forced outward, thereby decreasing the amount of tension exerted by the turnbuckle. Hence, the turnbuckle provides selectively adjustable tension.

In an alternative embodiment (not illustrated) the turnbuckle has one rod in threaded engagement with a body and a second rod mounted at an opposite end of the body on a swivel. Hence, rotation of the body causes only the first rod to displace either toward or away from the body.

The compression member 16 is U-shaped so as to define first and second ends 21 and 22 adapted for connection to the panel 2 within the central region 7. More particularly, the compression member is formed by a pair of arms 25 and 26, which are interlinked by an linking member 27. The position at which the arms 25 and 26

are connectable to the linking member is adjustable to allow for varying configurations of the compression member 16.

The compression member 16 also has first and second connection points 23 and 24 for connection of the first and second tension members 15 and 17 respectively. The first and second connection points 23 and 24 are respectively disposed on the arms 25 and 26 remote from the first and second ends 21 and 22. The compression member 16 defines a plane which, in use, is disposed substantially at right angles to an elongate axis 28 of the panel.

The first tension member 15, in conjunction with the first arm 25 and the part of the panel 2 extending directly from the first arm 25 to the first tension member 15, forms a first right angle triangle with the first tension member 15 as the hypotenuse. Similarly, the second tension member 17, in conjunction with the second arm 26 and the part of the panel 2 extending directly from the second arm 26 to the second tension member 17, forms a second right angle triangle with the second tension member 17 as the hypotenuse. For both of the first and second triangles, the tension respectively provided by the first and second tension members 15 and 17 creates a compressive force 10 directed along the first and second arms 25 and 26 towards the interior side 3 of the panel 2. For each arm 25 and 26 this compressive force 10 is communicated onto the panel 2 at each of the ends 21 and 22. This force assists to counter bulging by the panel 2 due to the weight of the concrete 4. Hence, the use of the brace 8 in the preferred embodiment of the present invention dispenses with the need that is otherwise present in at least some of the prior art for supports that extend between the panels through the concrete wall. In other words, it allows the preferred embodiment to function as a "single sided shutter". This is clearly advantageous if it is desired to produce a uniformly solid concrete wall. The preferred embodiment can function as a single sided shutter even when configured to support a column of concrete having a height of greater than 1.5 meters. For example, the standard height of each of the panels 2 in the preferred embodiment is approximately 3 meters, allowing for containment of a column of concrete having a height of approximately 3 meters. Indeed, the preferred embodiment allows for vertical stacking of panels 2,

potentially allowing for containment of columns of concrete having a height of approximately 6, 9 or 12 meters.

An upwardly directed component of the tension from the first tension member 15 is communicated into the linking member 27. Similarly, a downwardly directed component of the tension from the second tension member 17 is communicated into the linking member 27. Preferably the tensions of the first and second tension members 15 and 17 are matched such that these upward and downward force components cancel each other out.

In applications requiring more than one brace 8, as shown for example in figure 1, a spacer 29 may be utilised so as to maintain a suitable spacing between the adjacent braces 8.

As best shown in figure 3, a bridge 80 is disposed at the upper periphery 13 of a first panel 2 so as to span the separation distance between two facing panels. This bridge 80 provides further support to maintain the two panels at the desired separation distance. The length of the bridge 80 is adjustable to allow for multiple possible separation distances between the two facing panels.

The brace 8 shown in figures 1 to 11 is suitable for applications in which there is no external anchoring point. Such situations arise, for example, on the exterior walls of multi- story buildings. However, if an external anchoring point is available, for example by anchoring from the floor to an internal wall of a building, then the alternative preferred embodiment shown in figures 13 to 16 may be utilised. In such embodiments that turnbuckles 92 extend from floor anchor points 93 to connection points 94 on the central region 7 of the panels 2. Supplementary floor anchors 95 are also used to further secure the lower periphery 14 of the panel 2 in the desired position.

The Connection of Two Panels:

The following exemplary detailed description relates to the connection of a first panel 30 to a second panel 31, for example the two panels shown in figure 11. Each of the

panels 30 and 31 define first and second panel edges 32 and 33 respectively. (In fact, it will be appreciated that each panel 30 and 31 defines four sides, however this part of the description will focus predominantly upon the edges 32 and 33 that are connected to each other.) The first panel edge 32 defines a plurality of first panel apertures 34 disposed adjacent the first panel edge 32. Similarly, the second panel edge 33 defines a plurality of second panel apertures 35 disposed adjacent the second panel edge 33.

Placement of the two panel edges 32 and 33 adjacent each other defines two parallel rows of first and second panel apertures 34 and 35, with a substantially constant separation distance 39 being defined between respective first and second panel apertures 34 and 35. More particularly, the separation distance 39 is constant to within tolerances of equal to, or less than, approximately ±2 mm. This is because each panel is preferably manufactured to within tolerances of equal to, or less than, approximately +1 mm. In practice, the separation distance applicable to an external corner 40 is slightly greater than the separation distance applicable to an internal corner 41. This is due to the use of a fillet 42 (a cross section of which is shown in figure 22) which is inserted intermediate the first and second panel edges 32 and 33 at each external corner 40. The fillet 42 is required to plug the small gap between the first and second panel edges 32 and 33 that exists at each external corner 40. Such a gap is not formed between the first and second panel edges 32 and 33 at internal corners 41.

A variation of the fillet 81 (a cross section of which is shown in figure 21) is inserted intermediate two panels 30 and 31 that are connected to each other such that the lie in the same plane, which is referred to as a straight connection. The fillets 42 and 81 are typically constructed from a pliable material such as a plastics material.

A connection plate 36 has first and second connection plate apertures 37 and 38, which are separated by the applicable separation distance 39. This allows for alignment of the connection plate 36 such that the first connection plate aperture 37 is aligned with a selected one of the apertures 34 on the first panel 30. Similarly, the second connection plate aperture 38 is aligned with a selected one of the apertures 35

on the second panel 31. The connections plate 36 shown in figure 33 has four apertures, two of which, 37 and 38, are obstructed by fasteners 43 and 44. The other two, 82 and 83 provide optional additional connection points, if required.

Each of the panel apertures 34 and 35, and each of the connection plate apertures 37 and 38 have a substantially identical elongate shape. More particularly, the elongate shape is substantially rectangular, with slightly rounded corners. The longer side of the rectangle defines the major aperture axis 55 and the shorter side of the rectangle defines the minor aperture axis 56. This rectangular shape is selected so as to function in conjunction with the fasteners 43 and 44 in a manner described in detail later in this specification.

A first fastener 43 is insertable through the first connection plate aperture 37 and through the selected one of the apertures 34 on the first panel 30 so as to affix the connection plate 36 to the first panel 30. Similarly, a second fastener 44 is insertable through the second connection plate aperture 38 and through the selected one of the apertures 35 on the second panel 31 so as to affix the connection plate 36 to the second panel 31. Hence, the first panel 30 is effectively affixed to the second panel 31 via the connecting plate 36.

In practice, a plurality of connection plates 36 are used to connect each pair of panel edges 32 and 33. For example, as shown on Figure 1, five connection plates 36 are used to affix panel edge 32 to panel edge 33. The five connection plates 36 are spaced substantially regularly along the length of the panel edges 32 and 33.

As best shown in figure 35, each of the fasteners 43 and 44 include a wedge 45, which tapers from a wide end 46 to a thin end 47. The wedge 45 has a substantially constant thickness 52 and has chamfered edges 53 and 54.

Each of the fasteners 43 and 44 also include a shaft 48, which has an elongate head 49 shaped so as to correspond with the elongate shape of the panel apertures 34 and 35 and the connection plate apertures 37 and 38. That is, the elongate head 49 is substantially rectangular, with the longer side of the rectangle defining a major head

axis 57 and a line parallel to the shorter side of the rectangle defining minor head axis 58. The shaft 48 further includes a slot 50 for receiving the wedge 45. That is, the slot 50 has a width 51 that is slightly greater than the thickness 52 of the wedge 45. The length of the slot 50 is slightly greater than the maximum width of the wedge 45 at the wide end 46.

Each of the fasteners 43 and 44 further include a collar 59 which defines a collar aperture 60 for receiving the shaft 48. The collar 59 further defines a pair of projections 61 and 62. Each of the projections 61 and 62 have tapered ends 63 and 64. The projections 61 and 62 each define opposed faces 65 and 66 which are separated by a separation distance which is slightly greater than the width of the shaft head 49. Hence, provided the major head axis 57 of the shaft head 49 is parallel with the opposed faces 65 and 66, the separation distance 67 between the projections 61 and 62 provides sufficient clearance for the width (but not the length) of the shaft head 49. Hence, it is possible to thread the shaft 48 through the collar aperture 60 such that the shaft head 49 is disposed intermediate the projections 61 and 62, as shown in figure 34.

The shaft 48 has a slightly rectangular cross sectional shape. This combines with the slightly rectangular shape of the collar aperture 60 to ensure that it is only possible to thread the shaft 48 through the collar aperture 60 when the major head axis 57 of the shaft head 49 is parallel with the opposed faces 65 and 66. If, on the other hand, the major head axis 57 of the shaft head 49 is oriented at right angles to the opposed faces 65 and 66, it is not possible to thread the shaft 48 through the collar aperture 60. This guards against inadvertently inserting the shaft 48 into the collar aperture 60 in an incorrect orientation relative to the projections 61 and 62, thereby promoting operational efficiency.

The panel apertures 34 and 35 are formed at regular intervals within a beam 68 having two sides 69 and 70 that are disposed at right angles to each other. This type of beam skirts the periphery of each panel 2, 30 and 31. It also criss-crosses the length and width of each panel. Hence, a plurality of panel apertures 34 and 35 are regularly

spaced across the exterior side 5 of each of the panels 2, 30 and 31. This provides an abundance of possible connection points.

As shown in figures 24 and 26, each of the beams 68 are mounted to the interior side 5 of each of the panels 2, 30 and 31 such that the internal right angle of the beam 68 faces toward the exterior side 5 of the panel. As a result, each of the panel apertures 34 and 35 are disposed at substantially 45° relative to the elongate axis 28 of the panels 30 and 31. Due to this geometry, when two like panels 30 and 31 are placed at right angles to each other, as shown in figure 1, the adjacent rows of first and second panel apertures 34 and 35 are aligned in a single plane. As shown in figure 33. Hence, for the connection of two panels 30 and 31 that are at right angles to each other, it is possible to use a straight connection plate, as best shown in figures 7 and 33. On the other hand, to connect two panels 30 and 72 to each other such that the two panels lie in the same plane, it is necessary to use an alternative connection plate 71, which consists of two sides 73 and 74 joined to each other such that the connection plate apertures 37 and 38 are aligned at right angles to each other, as shown in figures 36 and 37. The connection plate apertures 37 and 38 on this type of connection plate 71 may then be aligned with two selected adjacent panel apertures 34 and 35, which are also oriented at right angles to each other. Such a connection is shown in figure 10. It will be appreciated by those skilled in the art that other geometries of panel connection are possible through the use of connection plates having suitably altered geometries.

The method of erecting the formwork apparatus 1 includes the steps of: positioning the first and second panels 30 and 31 such that their respective panel edges 32 and 33 are adjacent each other; aligning the appropriate connection plate 36 such that the first connection plate aperture 37 is aligned with a selected one of the apertures 34 on the first panel 30 and such that the second connection plate aperture 38 is aligned with a selected one of the apertures 35 on the second panel 31; inserting a first fastener 43 through the first connection plate aperture 37 and through the selected one of the apertures 34 on the first panel 30 so as to affix the connection plate 36 to the first panel 30; and

inserting a second fastener 44 through the second connection plate aperture 38 and through the selected one of the apertures 35 on the second panel 31 so as to affix the connection plate 36 to the second panel 31. In this manner the first panel 30 is effectively affixed to the second panel 31 via the connection plate 36.

More particularly, the step of "inserting a first fastener 43 through the first connection plate aperture 37 and through the selected one of the apertures 34 on the first panel 30 so as to affix the connection plate 36 to the first panel 30" includes the steps of: aligning the major head axis 57 of the shaft head 49 with the major aperture axis 55 of the first connection plate aperture 37; inserting the shaft head 49 through the first connection plate aperture 37 and through a selected one of the apertures 34 on the first panel 30; rotating the shaft 48 such that the major head axis 57 is substantially aligned with the minor aperture axis 56 of the selected one of the panel apertures, thereby captively retaining the shaft 48 within the selected one of the panel apertures 34; inserting the collar 59 onto the shaft 48 such that the projections 61 and 62 are aligned with the minor head axis 58 (that is, the opposed faces 65 and 66 of the projections 61 and 62 are parallel with the major head axis 57), and inserting the wedge 45 into the slot 50 so as to drive the projections 61 and 62 into the major aperture axis 55 of the connection plate aperture 37. Once the projections 61 and 62 have been forced into the connection plate aperture 37, it is no longer possible to rotate the fastener 43 relative to the panel 30. Hence, the shaft head 49 remains captively retained within, and effectively clamped against, the selected one of the panel apertures 34.

It will be appreciated by those skilled in the art that similar steps to those outlined in the above paragraph may be employed to use the second fastener 44 to affix the connection plate 36 or 71 to the second panel 31.

Advantageously, the preferred method of erecting the formwork apparatus can be carried out without a requirement for highly skilled tradesmen. Further, little or no specialised tools are required. Once the panels have been placed into the required

position, the only tool that is typically required is a hammer to drive the wedges 45 into the slots 50.

Another advantage of the preferred embodiment is that a single fixing methodology utilising variants of the fasteners 43 may be utilised for the majority of fastening requirements on the overall formwork structure. For example, fasteners 43, or slight variants thereof such as the plate-first fastener 84 (figure 29), the straight-plates fastener 85 (figure 30), and plate-last fastener 86 (figure 31), the top bridging fastener 90 (figure 32) and the slotted lugs 87, 88 and 89 on the arm 25, are utilised in at least the following contexts:

• Fastening of the panels 30 and 31 to each other, whether the panels are straight relative to each other, or forming a 90° internal corner, or a 90° external corner;

• Fastening of the compression members 16 to the central regions 7 of the panels 2;

• Fastening of the tension members 15 and 17 onto the upper and lower peripheries 13 and 14;

• Fastening of the bridges 80 onto the upper peripheries 13; and

• Fastening of the arms 25 and 26 of the compression members 16 onto the linking members 27 and the spacers 29.

To assist with lifting of the panels, for example by means of a crane, the lifting lug 91 (figure 28) is connectable to the upper periphery 13 of each of the panels 2, as shown in figure 16. This lug provides an aperture 96 for connection of the panel 2 to a crane or other lifting mechanism.

Yet another advantage of the preferred embodiment relates to the tolerances within which the fixing methodology functions. As compared to at least some of the prior art fixing methodologies , such as screw threads for example, the fixing methodology of the preferred embodiment does not require as much accuracy in the initial alignment of the components to be affixed. Rather the components may be slightly misaligned, for example within tolerances of equal to, or less than, approximately ±1 mm, and the

shaft head 49 will generally still be insertable into the selected panel aperture 34 and, upon rotation, will still be captively retained therein. In such situations, the tapered ends 63 and 64 of the projections 61 and 62, when driven into the connection plate apertures 37 or 38 by the force provided by driving of the wedge 45 into the slot, will typically align the components being affixed into the desired alignment, or at least somewhat closer thereto. For example, if adjacent panels 30 and 31 are slightly misaligned relative to each other, however are still within acceptable tolerances, the design and operation of the fastener 43 encourages self-alignment of associated components, for example of the fixing plates 36, generally to within more acceptable tolerances .

Whilst the invention has been described with reference to specific examples, those skilled in the art will appreciate that it may be embodied in many other forms.