GB2361943A

GB2361943A - Shuttering system

Info

Publication number: GB2361943A
Application number: GB0023341A
Authority: GB
Inventors: Richard Francis Biss; Edward Henry Clifford
Original assignee: CCP ASSOCIATES Ltd
Current assignee: CCP ASSOCIATES Ltd
Priority date: 2000-09-22
Filing date: 2000-09-22
Publication date: 2001-11-07
Anticipated expiration: 2020-09-22
Also published as: AU2001290072A1; GB0023341D0; WO2002025026A1; GB2361943B

Abstract

A system for assembly into self supporting shuttering for the casting therein of a beam (50) and a floor slab (60), the system comprising a base shutter component (20), a lower wall shutter component (10) and an upper wall shutter component (30). The components include locating means (12,16) to facilitate assembly of the system and to resist the forces experienced during casting.

Description

2361943 1- IMPROVEMENTS IN AND RELATING TO SHUTTERING The present

invention relates to self-supporting shuttering for the casting therein of a beam, which beam may be a beam for a foundation and more particularly 5 an edge beam of a raft foundation.

A prior art method of forming a mould for the casting therein -)f. concrete edge beam and slab of a raft foundation is shown schematically in Figure 8. In this method, a trench I is dug into the ground and a timber board 2 is disposed vertically at a side of the trench 1. The board requires the provision of supports (not shown) to prevent the board from toppling over under the action of the hydrostatic pressure of poured concrete. A laterally facing mould surface 3 of the timber board forms a shutter wall 2. This mould surface 3, and an upwardly facing surface 4 and a laterally facing surface 5 of the trench I itself, form a generally U-shaped mould for the casting therein of the edge beam 6, integrally with slab 8. In order to be able to lay bricks at a level below the surface of the ground at the edge of the trench it is necessary to avoid casting concrete right up to the top of the timber shutter wall 2. To achieve this a sacrificial shutter 7 made of for example polystyrene or cardboard is attached to the top of the timber shutter wall on its inside mould surface 3. In this way, by removing the sacrificial shutter 7 after casting, an upwardly facing surface 9 on which a course of bricks can be laid may be formed at or below ground and/or floor level at the outer edge of the slab 8 above the edge beam 6.

A problem with this prior art shuttering method is that the shuttering is difficult to assemble, requiring carpentry skills, and requires the timber board to be properly supported if the board is not to topple over either before casting, due to back-filling of the trench I with excavated earth (i.e. positioning earth on the left hand side of the timber 2 as shown), or during casting due to the pressure of the poured concrete. Additionally, it is a building requirement to have a damp-proof membrane between the ground and the concrete on the side wall 3 of the mould formed by the timber shutter and on the base 4 of the trench. It is complicated to arrange a damp-proof membrane around the shutter component before pouring concrete into the mould when a sacrificial shutter component 7 such as the one for forming the upwardly facing surface 9 for laying thereon of bricks is used.

In the first aspect of the present invention there is provided a system for assembly into a self-supporting shuttering for the casting therein of a beam, the system comprising a base shutter component, a lower wall shutter component and an upper wall shutter component, the lower wall shutter component being provided with first and second locating portions, the base shutter component being provided with a third locating portion and the upper wall shutter component being provided with a fourth locating portion, whereby the first and third locating portions are engageable to locate the lower wall shutter component on the base shutter component when the lower wall shutter component is assembled on the base shutter component and the second and fourth locating portions are engageable to locate the upper wall shutter component on the lower wall shutter component when the upper wall shutter component is assembled on the lower wall shutter component, whereby the assembled shutter components form the self-supporting shuttering.

The hereinafter described embodiment of the present invention allows shuttering to be easily assembled from dry components without the need for motar joints or to glue or nail the components of the shuttering together. The components of the self-supporting shuttering can be carried to the site and assembled there without the need for mechanical lifting machinery. Also there is no need to attach additional sacrificial polystyrene shuttering to form an upwardly facing surface for bricks. The shuttering components allow for easy attachment of a damp-proof membrane.

In a second aspect of the present invention there is provided a selfsupporting shuttering for the casting therein of a beam, said self-supporting shuttering comprising: a lower wall shutter component provided with first and second locating - a base shutter component provided with a third locating portion- d portions,. an an upper wall shutter component provided with a fourth locating portion; wherein said lower wall shutter component is located on said base shutter component by engagement of said first and third locating portions; and said upper wall shutter component is located on said lower wall shutter component by engagement of said second and fourth locating portions.

In a third aspect of the present invention there is provided a method of assembling a self-supporting shuttering for the casting therein of a beam, the method comprising the steps of providing a lower wall shutter component with first and second locating portions; assembling said lower wall shutter component on a base shutter component by engaging said first locating portion with a third locating portion on said base component thereby to locate said lower wall shutter component on said base shutter component; and assembling an upper wall shutter component provided with a fourth locating portion on said lower shutter wall component by engaging said second locating portion with said fourth locating portion thereby to locate said upper wall shutter component on said lower wall shutter component.

The present invention will now be described by way of example only with reference to the following drawings in which:

Figure I is a schematic perspective view of an embodiment of selfsupporting shuttering and foundation according to the present invention; Figure 2 is a schematic longitudinal cross-section of the lower wall shutter component of Figure 1; Figure 3 is a schematic longitudinal cross-section of the base shutter component of Figure 1; Figure 4 is a schematic longitudinal cross-sectional view of the upper wall shutter component; Figure 5 is a schematic longitudinal cross-section of a self-supporting shuttering and foundation according to the present invention; Figure 6 is a perspective view of a self-supporting shuttering according to the present invention; Figure 7 is a perspective view of a self-supporting shuttering according to the 4- present invention-, and Figure 8 is a schematic longitudinal cross-section through a prior art shuttering arrangement with a foundation cast therein.

The self-supporting shuttering shown in Figure I can be assembled from three main shutter components which make up a system for assembly into a selfsupporting shuttering for the casting therein of a concrete beam. The three main components are a lower wall shutter component 10, a base shutter component 20 and an upper wall shutter component 30.

The lower wall shutter component 10 is provided with a first locating portion 12 and a second locating portion 14 to enable it to be located on the base shutter component 20 and to enable the upper wall shutter component 30 to be located on it respectively. For this purpose the base shutter component 20 is provided with a third locating portion 22,24 which is engageable with the first locating portion 12 and the upper wall shutter component 30 is provided with a fourth locating portion 32, 3 8, which is engageable with the first locating portion 14 of the lower wall shutter componentIO. By assembling the lower wall shutter component 10 on the base shutter component 20 with the first and third locating portions engaged the lower wall shutter component 10 can be locked to the base shutter component 20, as will be described below. By assembling the upper wall shutter component 30 on the lower wall shutter component with the second and fourth locating portions engaged the upper wall shutter component 30 can be locked to the lower wall shutter component 10, as will be described below. In this way the shutter components can be assembled to form a self-supporting shuttering.

In order to enable a course of bricks to be laid subsequently on the upwardly facing surface 36 of the upper wall shutter component 30, so that the course of bricks can be at or below the level of the concrete to be cast in the shuttering, the upper wall shutter component may, as shown, be provided with supporting means 34 for supporting a top wall shutter component 40. In the illustrated embodiment the supporting means take the form of a recess 34 in the upwardly facing surface 35 of the upper wall shutter component 30. The top wall shutter component 40 is provided 5with means for co-operating with the supporting means. In the illustrated embodiment these cooperating means take the form of the lower edge of the top wall shutter component 40. By engaging that lower edge in the recess 34, the top wall shutter component 40 can be assembled and supported on the upper wall shutter 5 component 30.

Preferably the upper 3 0 and lower 10 wall shutter components and the base shutter component 20 are fabricated in concrete, or a polymer based concrete, whilst the top wall shutter component 40 is a metal or wooden sheet. Preferably the top wall shutter component 40 is comprised of a corrugated metal sheet to increase its stiffness and thereby reduce the thickness, weight and cost of the metal sheet required.

As can be seen from Figure 1, when assembled the shutter components 10,20, 30,40 form a generally L-shaped shuttering when viewed in longitudinal transverse cross-section. The upwardly facing surface 35 of the upper wall shutter component 30 and the upwardly facing surface 16 of the lower wall shutter component 10 are elongate. The width of the upwardly facing surface 35 of the upper wall shutter component 30 in a direction perpendicular to the elongate direction of that component is larger than the width of the upwardly facing surface 16 of the lower wall shutter component 10 in the same direction. Theupperwall shutter component 30 thus overhangs the lower wall shutter component 10 on both sides. In this way it is possible to minimise the weight of the components of the selfsupporting shuttering whilst still enabling the self-supporting shuttering, when assembled, to present a surface along which a course of bricks 90 may be laid. Conveniently, when the course of bricks 90 is laid along the top surface 36 of the upper wall shutter component 30, spaced away from the top wall shutter component 40, a wall cavity 92 is formed between the course of bricks 90 and the top wall shutter component 40.

A procedure for assembling the illustrated embodiment of shuttering will now be described. The initial step is to dig a generally U-shaped trench in the ground.

Next, wet mortar is placed in the bottom of the trench so that a plurality of base shutter components 20, 120, 220 can be laid on the mortar in a substantially horizontal plane abutting each other end to end with their third locating portions generally aligned, as shown in Figure 1. A plurality of lower wall shutter components 10, 110, 2 10 are then assembled onto the base shutter components to abut each other end to end and with their first locating portions engaging the third locating portions of the base shutter components, again as shown in Figure 1.

Finally, a plurality of upper wall shutter components 30, 130, 230 are assembled onto the lower wall shutter components 10, 110,210 to abut each other end to end and with their fourth locating portions engaging the second locating portions of the lower wall shutter components. In this way a longitudinal run of self-supporting shuttering can be assembled.

The strength and stability of the self-supporting shuttering can be increased by staggering the joins of the layers of components, as shown. For example, the abutted pairs of ends 100 of the base shutter components 20, 120, 220, are arranged such that they do not vertically align with the abutted pairs of ends 115 of the lower wall shutter components 10, 110, 210. Additionally, the abutted pairs of ends 125 of the upper wall shutter components 30, 130, 230 are not vertically aligned with the abutted pairs of ends 115 of the lower shutter component 10, 110, 2 10. This staggering of the joins has the effect of the upper wall shutter components and the base shutter components holding adjacent lower wall shutter components together, with a corresponding increase in strength and stability. Where the three main shutter components 10,20,30 all have the same length, for example 600 trim, the abutted pairs of ends 100 of the base shutter components, 20, 120, 220 and the abutted pairs of ends 125 of the upper wall shutter components 30, 130, 230 are preferably aligned and the abutted pairs of ends 115 of the lower wall shutter components 10, 110, 210 are positioned approximately half way along the length of the base shutter components 20, 120, 220 and the upper wall shutter components 30, 130, 230, as shown in Figure 1.

A laterally facing surface 70 of the trench, an upwardly facing surface 26 of the base component 20, a laterally facing surface 18 of the lower wall shutter component 10 and the laterally facing surface 3 6 of the upper wall shutter component 30 define a mould having a generally U-shaped cross- section. The laterally facing surfaces 70, 18,36 are surfaces with at least some vertical component. Any residual trench space to the side of the lower wall shutter component 10 that is opposite to the 5 laterally facing surface 70 may be back filled such that earth abuts the left hand side (as drawn) of the lower and upper wall shutter components 10, 20.

In the preferred embodiment described, the locating portions are fon-ned as locking portions to substantially prevent movement apart as well as relative sliding movement of the lower wall shutter component 10 to the base shutter component 20 and the upper wall shutter component 30 relative to the lower wall shutter component.

As can be seen from Figure 2, the first locating portion, at one edge of the lower wall shutter component 10, comprises a triangular shaped lipreceiving recess 12 which runs adjacent the edge of the generally elongate slab shaped lower wall shutter component 10 on the moulding surface 18. The third locating portion of the base shutter component 20, as shown in Figure 3, comprises a recess 22 in the moulding surface 26 of the base shutter component 20 running adjacent, but spaced apart from, an edge with a generally triangular shaped lip 24 protruding laterally into the recess 22. The protrusion of the lip 24 into the recess causes the lip to overhang the base of the recess 22. The top surface of the lip is Rush with the moulding surface 26.

During assembly of the self-supporting shuttering in the trench, after arranging the base shutter component(s) generally horizontally, the first locating portion is placed into the recess 22 in a base shutter component 20 whilst an acute angle is maintained between moulding faces 18,26 of the lower wall shutter component 10 and the base shutter component 20. The lower wall shutter component 10 is then pivoted around its first locating portion relative to the base shutter component 20 (in an anti-clockwise direction as drawn) to increase the angle between the moulding faces 18,26 and thereby to engage the lip 24 of the third locating 3 0 portion in the lip-receiving recess 12 of the first locating portion 10. In the illustrated a embodiment the I ower wall shutter component 10 is pivoted by an amount such that the moulding faces 18,26 of the lower wall shutter component 10 and of the base shutter component 20 end up substantially perpendicular to one another. It will however be appreciated that for a forming beam of other cross-sectional shapes, the moulding faces of these two components need not be substantially perpendicular to one another. In such an alternative arrangement, the geometry of the locating portions would require modification.

The engagement of the laterally protruding lip 24 in the lip-receiving recess 12 means that the lower wall shutter component 10 is locked to the base shutter component 20 to resist the tendency for lateral sliding movement, as well as upward movement, of the lower wall shutter component 10 relative to the base shutter component 20, as well as resist further pivoting of the lower wall shutter component relative to the base shutter component 20 occasioned by the action of casting the beam. When casting a concrete beam, hydrostatic forces can be quite high and the laterally protruding lip 24 engaging in the lip-receiving recess 12 resists the action of these forces. To make assembly easier, the recess 22 in the base shutter component may be made oversize, necessitating the insertion of a spacer element into the back of the recess 22 between the base shutter component 20 and the lower wall shutter component 10 on the side opposite the moulding surface 18 to help to j am the lower wall shutter component 10 into the recess 22 of the base shutter component 20.

These spacer elements may, for example, be wedges fabricated in wood, concrete or any other suitable material.

The second locating portion of the lower wall shutter component 10, as shown in Figure 2, comprises a laterally protruding lip 14 which extends beyond the moulding surface 18 of the lower wall shutter component 10 to overhang the base shutter component 20 and is of generally a triangular cross-section. In this way, the first and second locating portions are provided on opposite longitudinal elongate edges of the moulding surface 18 of the generally slab-shaped lower wall shutter component 10.

The fourth locating portion 32 of the upper wall shutter component is shown g- in Figure 4 and comprises a lip-receiving lateral recess 32 for receiving the laterally protruding lip 14 of the second locating portion. The lip- receiving lateral recess 32 is formed in a portion of the upper wall shutter component 30 which, in use, overhangs the base shutter component 10 and extends down the moulding surface 18 of the 5 lower wall shutter component 10.

A back lip 38 may, as shown, be provided as part of the fourth locating portion on the upper wall shutter component 30 to co-operate with the back surface of the lower wall shutter component, this back surface being the surface opposite to the moulding surface 18 when assembled. In use, the back lip 38 can help to lock the upper wall shutter component 30 to the lower wall shutter component 10 to prevent misalignment and sliding movement of the upper wall shutter component 30 relative to the lower wall shutter component 10.

In the illustrated embodiment, once the lower wall shutter component 10 has been pivoted into final position, the upper wall shutter component 30 may be assembled on the lower wall shutter component 10. If the optional back lip 3 8 is provided on the upper wall shutter component, as is illustrated in Figures 1 and 4, assembly is achieved by first orientating the upper wall shutter component 30 such that its moulding surface 36 is positioned to face the laterally facing wall 70 of the trench and the back lip 38 is close or in contact with the upwardly facing surface 16 of the lower wall shutter component. The upper wall shutter component 30 is then moved relative to the lower wall shutter component in a direction away from the laterally facing wall 70 of the trench until the back lip 38 can engage behind the back surface of the lower wall shutter component 10. This happens by a pivoting action of the upper wall shutter component 30 around the lip receiving lateral recess 32 and lip 14. If there is no back lip, as denoted by the dotted lines in Figure 4, the upper wall shutter component 30 may be assembled on the lower wall shutter component by being slid into place without the above-mentioned pivoting action.

When engaged, the laterally protruding lip 14 and lip-receiving lateral recess 32 resist the tendency of the upper wall shutter component 30 to move laterally (to the left as drawn) as well as upwardly relative to the lower wall shutter component 10 10- occasioned by the action of casting of a beam in the generally U-shaped mould.

It will be appreciated that the locating portion may be configured differently to those in the illustrated embodiments and still have the effect of holding the various shutter components together to enhance overall stability of the assembled shuttering.

The depth of the trench and the height of the main shutter components may be adjusted such that the upwardly facing surface 35 of the upper wall shutter component 30 is substantially level with or below the edge of the trench. In this way, the outer bricks 90 of a building can start at or below the level of the ground which is aesthetically more appealing than having concrete visible above the level of the ground.

If it is desired to integrally form a slab 60 of a raft foundation with the beam to be cast in the trench, with the slab having an upwardly facing surface above the level of the upwardly facing surface 36 of the upper wall shutter component 30, the top wall shutter component 40 is assembled onto the upper wall shutter component 30. This arrangement allows a course of bricks to be laid below the level of the upwardly facing surface of the raft as well as at or below the edge of the trench.

Once the upper wall shutter components 30 have been assembled onto the lower wall shutter components, the top wall shutter components 40 can be assembled onto the upper wall shutter components 30 by inserting edge portions of the top wall shutter components 40 into the recesses 34 in the upwardly facing surfaces 36 of the upper wall shutter components 30 to support the top wall shutter components 40. This enables the height of the shuttering to be sufficient to cast a beam and a slab of a raft foundation whilst still presenting an upwardly facing surface 36 at or below the edge of the trench along which a course of bricks 90 may be laid and below the level of the slab 60.

The shutter wall components are preferably made both of a material and of a size such that the components of the self-supporting shuttering can be readily carried by one or two people and easily assembled without the need for special skills. The weight of each component is advantageously under 50 kg, preferably less than 30 kg.

The components may be cut by an angle grinder. To simplify the action of 11- staggering the joins of the different layers of the main shutter components, the main shutter components 10,20,30 are all of the same length, for example 600 mm long in their an elongate direction (dimension W in Figure 1). The base shutter component may be 450 mm wide and 15 nim thick. The lower wall shutter component may be 75 mm thick and 240 mm. high. The top wall shutter component may be 115 mm thick at its maximum thickness and 190 mm wide at its maximum width. When assembled, the upper wall shutter component 30 may extend the height of the shuttering by about 65 mm. It is envisaged that the main shutter components will all be at least 0.3 m long, that the base shutter component 20 will be at least 0.2 m wide and 0.01 thick, that the lower wall shutter component will beat least 0.3 m high and 0. 0 1 m thick and that the maximum height of the upper wall shutter component will be at least 0.05 m and the maximum thickness will be at least 0. 15 m. It will be appreciated that the components may readily be supplied in other sizes and/or materials.

Using the shuttering assembled in a trench, a beam 50 can be cast in the generally U-shaped mould integrally with the slab 60 of a raft foundation assembly.

The upwardly facing surface of the raft 60 may be used to form the floor of a building. To enable the formation of a cavity wall, a further course of bricks (not shown) may be built on the edge of the slab 60, and the built up like course 90, to form a pair of parallel walls with a cavity therebetween.

Current building regulations require that the foundation of a building is damp-proofed against water ingress from the ground. In Figure 1, a dampproof membrane 80 (denoted by a dotted line) is placed along the entire surface of the generally U-shaped mould as well as along the ground onto which the slab 60 of the raft foundation is to be cast. The damp-proof membrane may also extend beyond the top of the top wall shutter component 40 to lap with a damp-proof course which would be laid under the internal skin of the building as described below in con unction with Figure 5.

j An alternative arrangement to the one illustrated in Figure 1 is to danip- proof the shutter wall components by painting them with bituminous paint. In such a case a damp proof membrane laid on top of the ground onto which slab 60 is to be cast is lapped to base shutter component 20. This arrangement can also be used without applying bituminous paint to the main shutter components 10, 20, 30 if those components are made of a material which is substantially impermeable to water, for 5 example a polymer based concrete.

The modular nature and ease of assembly of the illustrated embodiment of self-supporting shuttering allow the shuttering to be assembled without the need for fasteners or various glues. It is anticipated that the beam and raft foundations which can be cast using the illustrated embodiment of self-supporting shuttering will be able to meet today's building regulations for one and two storey buildings and when used in conjunction with a piling system would be suitable for almost any building.

Figure 5 shows an embodiment of the invention in which several further features, which may be used together, individually or in any combination have been incorporated.

In order to minimise the possibility of relative movement between the base and lower wall shutter components 20, 10 during casting of the beam, as shown a lower wedge or lower wedges 210 can be driven into the recess 22 of the third locating portion on the opposite side to lip 24 and abutting the lower wall shutter component 10 to lock the first locating portion in the recess 22 of the third locating portion.

Similarly, an upper wedge or upper wedges 220 can be driven between the back lip 3 8 of the fourth locating portion and the lower wall shutter component 10 thereby to assist in preventing relative movement between the upper and lower wall shutter components 10, 30 during casting of the beam.

A metal clip can also be used, if necessary, to improve the resistance of the assembled main components 10, 20, 30 to toppling over prior to the casting of the beam. The clip 230 is of a generally U-shaped construction and, when attached to the assembled main components, engages the base shutter component on a face 28 which is on the other side of the base shutter component to the moulding surface 26 and the upwardly facing surface 35 of the upper wall shutter component 30.

Conveniently the metal clip 230 can be removed after the casting of the beam and prior to back filling of earth against the shutter wall components.

It is also possible to manufacture the lower wall shutter component 10 integrally with reinforcing members 250 protruding from the moulding surface 18 into the area into which the beam is to be cast. In the illustrated embodiment these take the form of a plurality of closed loops of metal in spaced apart relationship to each other along the elongate direction of the lower wall shutter component 10. As will be understood, any shape or configuration (eg spiral) of reinforcing members 250 can be utilised. If required, links 260 (eg in the form of bars) may be attached to the reinforcing members to maintain the spacing of the reinforcing members 250 in the elongate direction of the lower wall shutter component 10. Also, supporting blocks 270 may be used to transfer the load of the reinforcing members 250 to the base shutter component 20 before casting of the beam to support the reinforcing members 250. If reinforcing members 250 are used, which are preferably steel, damp proofing of the shuttering may be achieved by applying liquid bituminous paint to the shutter components 10, 20, 30. This can either be applied at the manufacturingstage or after assembly of the shuttering. The use of reinforcing elements 250 advantageously provides shear reinforcement between the precast shutter components and the final cast beam.

The raft 60 of the foundation may, as illustrated in Figure 5, also be reinforced by raft reinforcing members 280, 290 supported by reinforcing members 250. If the foundation is to be supported by piles, these are positioned under the base shutter component 20 in a position approximately as indicated by 300 in Figure 5.

If the shuttering is supported by piles, the optimum position for the raft reinforcing members is lower (position 280) than the optimum position (position 290) for the case where the foundation is not supported by piles.

A course of bricks 304, above ground level, built on top of the cuurse of bricks 90 is separated from the course of bricks 90 by a damp-proof membrane 3. An inner course of bricks 300 is built on a top surface of the raft 60 of the foundation.

The inner course of bricks is also damp-proofed from the foundation by a sheet 305 which is lapped to the damp-proofing of the main shutter components, for example to the damp proof membrane 80.

The skilled person will recognise that there are several ways in which the shuttering can be arranged to accommodate changes in direction. Two examples are shown schematically in Figures 6 and 7.

Figure 6 shows how the direction of the shuttering might be changed through a small angle. Standard base and lower wall shutter components 20, 10 (as described above in relation to Figures I to 4) can be used, albeit cut to shape. In this regard two comer base shutter components 20' are cut along the moulding surface 26 and perpendicular thereto such that, when the cut ends of the two comer base shutter components 20' abut each other, their third locating portions lie at the desired angle to each other. The ends of the comer lower wall shutter components 10' are cut to the desired angle (i.e. not perpendicular to the moulding surface 18) such that those cut ends abut each other when the comer lower wall shutter components 10' are assembled onto the comer base shutter components 20'.

The comer upper wall shutter component 30' is manufactured as a single component and is essentially in the shape of two upper wall shutter components joined together at an angle end to end. It comprises all of the features of the standard upper wall shutter component mentioned above except for one of either back lip 38 or recess 32, such that it can be assembled onto the two comer lower wall shutter components 20'without rotation. As in the embodiment shown in Figure 1, the main shutter components 10, 20, 30 are staggered in the longitudinal direction to improve strength. This is achieved by the choice of length of the comer shutter components 10', 20', 3 0'.

Figure 7 illustrates a further method of changing the direction of the shuttering. The base shutter components 20 are all standard (i.e. as discussed in relation to Figures I to 4) and uncut. Two longitudinal runs of base shutter components 20 come together with their third locating portions at approximately 90' to each other. The comer lower wall shutter component 10"is generally L- shaped with only the base of the L-shape provided with a first locking portion which engages with the third locking portion of one of the base shutter components 20. The comer upper wall shutter component 3 0" is also generally L-shaped and is otherwise the same as comer upper wall shutter component 30'. The size of the comer components are preferably chosen such that the main components are longitudinally staggered to 5 increase the strength of the assembled shuttering.

16-

Claims

I A system for assembly into a self-supporting shuttering for the casting therein of a beam, the system comprising a base shutter component, a lower wall shutter component and an upper wall shutter component, the lower wall shutter component being provided with first and second locating portions, the base shutter component being provided with a third locating portion and the upper wall shutter component being provided with a fourth locating portion, whereby the first and third locating portions are engageable to locate the lower wall shutter component on the base shutter component when the lower wall shutter component is assembled on the base shutter component and the second and fourth locating portions are engageable to locate the upper wall shutter component on the lower wall shutter component when the upper wall shutter component is assembled on the lower wall shutter component, whereby the assembled shutter components form the self-supporting shuttering.
2. A system according to claim 1, wherein said upper wall shutter component is provided with supporting means for supporting a top wall shutter component.
3. A system according to claim 2, further comprising a said top wall shutter component, said top wall shutter component being provided with means for cooperating with the supporting means, to enable the top wall shutter component to be assembled on the upper wall shutter component to extend the height of the self- supporting shuttering.
4. A system according to claim 3, wherein said top wall shutter component is a metal sheet.
5. A system according to claim 2, 3 or 4, wherein said means for supporting is a recess provided in a surface of said upper wall shutter component that will be upwardly facing when said self-supporting shuttering is assembled.
6. A system according to any one of claims I to 5, wherein said upper wall shutter component has a generally longitudinal upwardly facing surface along which a course of bricks can be laid when said shuttering is assembled.
7. A system according to any one of claims I to 6, wherein said system comprises a plurality of each of said three shutter components, suitable for assembly together to form a longitudinal run of self-supporting shuttering.
8. A self-supporting shuttering for the casting therein of a beam, said self-supporting shuttering comprising: a lower wall shutter component provided with first and second locating portions; a base shutter component provided with a third locating portion; and an upper wall shutter component provided with a fourth locating portion; wherein said lower wall shutter component is located on said base shutter component by engagement of said first and third locating portions; and said upper wall shutter component is located on said lower wall shutter component by engagement of said second and fourth locating portions.
9. A system or self-supporting shuttering according to any one of the preceding claims, wherein upwardly facing surfaces of said upper and lower wall shutter components are elongate and the width of the upwardly facing surface of said upper wall shutter component in a direction perpendicular to the elongate direction thereto is larger than the width of the upwardly facing surface of said lower wall shutter component in a direction perpendicular to the elongate direction thereto when said self-supporting shuttering is assembled.
10. A system or self-supporting shuttering according to any one of the preceding claims, wherein said lower wall portion is a generally elongate slab, with 18- the first and second locating portions being provided on opposite longitudinal edges respectively.
11. A system or self-supporting shuttering according to any one of the preceding claims, wherein said base shutter component is slab shaped and said third locating portion is adjacent an edge on a slab face.
12. A system or self-supporting shuttering according to any one of the preceding claims, wherein the first and third locating portions are adapted, when engaged, to resist the tendency of lower wall shutter component to move laterally relative to the base shutter component occasioned by the action of casting the beam.
13. A system or self-supporting shuttering according to any one of the preceding claims, wherein the second and fourth locating portions are adapted, when engaged, to resist the tendency of the upper wall shutter component to move laterally relative to the lower wall shutter component occasioned by the action of casting the beam.
14. A system or self-supporting shuttering according to any one of the preceding claims, wherein the first and third locating portions are adapted, when engaged, to resist the tendency of the lower wall shutter component to pivot relative to the base s hutter component about the line of their engaged locating portions occasioned by the action of casting the beam.
15. A system or self-supporting shuttering according to any one of the preceding claims, wherein said first and third locating portions are adapted, when engaged, to lock said lower wall shutter component to said base shutter component.
16. A system or self-supporting shuttering according to preceding claim 15, wherein the first and third locating portions are adapted, when engaged, to resist 19- the tendency of upward movement of the lower wall shutter component relative to the base shutter component occasioned by the action of casting the beam.
17. A system or self-supporting shuttering according to claim 15 or claim 16, wherein said first and third locating portions allow, when engaged, relative rotation in one direction only of said lower wall component to said base component.
18. A system or self-supporting shuttering according to any one of claims 15 to 17, wherein said third locating portion comprises a recess and a lip protruding laterally into said recess and said first locating portion comprises a lipreceiving recess for receiving said lip when said first and third locating portions are engaged.
19. A system or self-supporting shuttering according to claim 18, wherein the protrusion of said lip into said recess causes the lip to overhang the base of the recess.
20. A system or self-supporting shuttering according to any one of the preceding claims, wherein said second and fourth locating portions are adapted, when engaged, to lock said upper wall shutter component to said lower wall shutter component.
21. A system or self-supporting shuttering according to claim 20, wherein said second locating portion comprises a laterally protruding lip and said fourth locating portion comprises a lip-receiving lateral recess for receiving said laterally protruding lip when said second and fourth locating portions are engaged.
22. A system or self-supporting shuttering according to claim 20 or claim 21, wherein, when said self-supporting shuttering is assembled, the portion of said upper wall shutter component forming said fourth locating portion extends down an inner face of said lower wall shutter component to overhang the base shutter component.
23. A system or self-supporting shuttering according to anyone of the preceding claims, wherein said base shutter component is generally slab shaped, and of a dimension of at least 0.2 m x 0.3 m x 0.01 m.
24. A system or self-supporting shuttering according to anyone of the preceding claims, wherein said wall shutter components are elongate and at least 10 0.3 m long in said elongate direction.
25. A system or self-supporting shuttering according to claim 24, wherein said lower wall shutter component is at least 0.3 m high and 0.01 m thick as orientated when said self-supporting shuttering is assembled. 15
26. A system or self-supporting shuttering according to claim 24 or 25, wherein said upper wall shutter component has a maximum height of at least 0.05 m and a maximum thickness of at least 0. 15 m as orientated when said self-supporting shuttering is assembled. 20
27.. A system or self-supporting shuttering according to anyone of the preceding claims, wherein each of said three shutter components weighs less than 50 Kg.
28. A self-supporting shuttering according to claim 8, or any one of claims 9 to 27, when dependent from claim 8, further comprising a top wall shutter component, wherein said upper wall shutter component is provided with supporting means for supporting said top wall shutter component and said top wall shutter component is assembled on said upper wall shutter component and supported by said supporting means to extend the height of the self-supporting shuttering.
29. A self-supporting shuttering according claim 8 or claim 28, or any one of claims 9 to 27 when dependent from claim 8, wherein a course of bricks is laid on an upper surface of said upper wall shutter component.
30. A self-supporting shuttering according to claim 28, wherein a course of bricks is laid along an upper surface of said upwardly facing wall shutter component alongside said top wall shutter component thereby forming a cavity between said top wall shutter component and said course of bricks.
31. A self-supporting shuttering according to any one of claims 8 or 28 to 30, or any one of claims 9 to 27 when dependent from claim 8, wherein said lower wall shutter component has a laterally facing surface which is generally perpendicular to an upwardly facing surface of said base shutter component.
32. A self-supporting shuttering according to any one of claims 8 or 28 and 3 1, or any one of claims 9 to 27 when dependent from claim 8, wherein said self supporting shuttering comprises a plurality of each of said lower wall shutter component, said base shutter component and said upper wall shutter component.
33. A self-supporting shuttering according to claim 32, wherein said base shutter components are assembled to abut each other end to end and lie in a first substantially horizontal plane with their third locating portions generally aligned, said lower wall shutter components are assembled on said base shutter components to abut each other end to end with their first locating portions engaging the third locating portions, and said upper wall shutter components are assembled on said lower wall shutter components to abut each other end to end with their fourth locating portions engaging said second locating portions.
34. A self-supporting shuttering according to claim 33, wherein abutted pairs of ends of the lower wall shutter components are not vertically aligned with -22. abutted pairs of ends of the upper wall shutter components.
35. A self-supporting shuttering according to claim 33 or claim 34, wherein abutted pairs of ends of the lower wall shutter components are not vertically 5 aligned with abutted pars of ends of the base shutter components.
36. A self-supporting shuttering according to any one of claims 8 or 28 to 35, or any one of claims 9 to 27 when dependent from claim 8, wherein in said selfsupporting shuttering is positioned in a trench, whereby a side of said trench, an upwardly facing surface of said base component and laterally facing surfaces of said lower and upper wall shutter components define a mould having a generally Ushaped cross-section for the casting therein of said beam.
37. A self-supporting shuttering according to claim 36, wherein the upwardly facing surface of said upper wall shutter component is below the level of an edge of said trench.
38. A self-supporting shuttering according to claim 36 or claim 37, wherein a damp-proof membrane is placed over the upwardly facing surface of said base component and the laterally facing surfaces of said lower and upper wall shutter components.
39. A self-supporting shuttering according to any one of claims 36 to 38, wherein a beam is cast in said mould.
40. A self-supporting shuttering according to any one of claims 36 to 39, wherein said self-supporting shuttering acts as shuttering for at least part of a concrete edge beam of a raft foundation.
41.A self-supporting shuttering according to claim 40, wherein an upwardly facing surface of said raft foundation is generally level with the top of the self-supporting shuttering.
42. A foundation comprising a self-supporting shuttering according to any one of claims 8 oi-28 to 41, orany one of claims 9 to 27 when dependent fromclaim 8.
43. A system or self-supporting shuttering according to any one of claims I to 4 1, wherein said base shutter component, said lower wall shutter component and said upper wall shutter component are fabricated from concrete.
44. A system or self-supporting shuttering according to any one of claims I to 4 1, wherein said base shutter component, said lower wall shutter component and said upper wall shutter component are fabricated from a polymer based concrete.
45. A method of assembling a self-supporting shuttering for the casting therein of a beam, the method comprising the steps of providing a lower wall shutter component with first and second locating portions; assembling said lower wall shutter component on a base shutter component by engaging said first locating portion with a third locating portion on said base component thereby to locate said lower wall shutter component on said base shutter component; and assembling an upper wall shutter component provided with a fourth locating portion on said lower shutter wall component by engaging said second locating portion with said fourth locating portion thereby to locate said upper wall shutter component on said lower wall shutter component.
46. A method according to claim 45, further comprising the step of assembling atop wall shutter component on said upper wall shutter component by engaging said top wall shutter component with said upper wall shutter component to thereby extend the height of the self-supporting shuttering.
47. A method according to claim 46, wherein said step of assembling said top wall shutter component comprises lowering said top wall shutter component into a recess provided on an upwardly facing surface of said upper wall shutter component.
48. A method according to any one of claims 45 to 47, wherein said first and third locating portions, when engaged, lock said lower wall shutter component to said base shutter component.
49. A method according to claim 48, wherein said step of assembling said lower wall shutter component on said base shutter component comprises the steps of.

placing said first locating portion into a recess in said base shutter component which forms said third locating portion whilst maintaining an acute angle between moulding faces of said lower wall shutter component and said base shutter component; and pivoting said lower wall shutter component relative to said base shutter component to increase the angle between the lower wall shutter component and the base shutter component to thereby engage in a lip-receiving recess of said first locating portion a lip protruding laterally into said recess of said third locating portion whereby to resist the tendency for lateral movement and upward movement of the lower wall shutter component relative to the base shutter component and for further pivoting of the lower wall shutter component relative to the base shutter component occasioned by the action of casting the beam.
50. A method according to any one of claims 45 to 49, wherein said second and fourth locating portions, when engaged, lock said upper wall shutter component to said lower wall shutter component.
51. A method according to claim 50, wherein said step of assembling an upper wall shutter component on said lower wall shutter component includes locking a laterally protruding lip which is part of said second locating portion into a lipreceiving lateral recess which forms part of said fourth locating portion whereby to resist the tendency for movement of said upper wall shutter component relative to said lower wall shutter component occasioned by the action of casting the beam.
52. A method according to any one of claims 4 5 to 5 1, further comprising the step of digging a trench in the ground and placing said base shutter component at the bottom of said trench prior to said assembling steps whereby a side of said trench, an upwardly facing surface of said base shutter component and laterally facing surfaces of said upper and lower wall shutter components define a mould having a generally U-shaped cross-section for the casting therein of said beam.
53. A method according to claim 52, further comprising the step of covering the upwardly facing surface of said base component and the laterally facing surfaces of said lower and upper wall components with a damp proof membrane.
54. A self-supporting shuttering for the casting therein of a beam substantially as hereinbefore described with reference to and as illustrated in the accompanying Figures.

54. A method according to any one of claims 45 to 53, further comprising the step of laying a course of bricks along an upwardly facing surface of said upper wall shutter component.

55. A method according to any one of claims 45 to 54, wherein a plurality of base shutter components are assembled to abut each other end to end and lie in a first substantially horizontal plane with their third locating portions generally aligned, a plurality of lower wall shutter components are assembled on said base shutter components to abut each other end to end with their first locating portions engaging said third locating portions, and a plurality of upper wall shutter components are assembled on said lower wall shutter components to abut each other end to end with their fourth locating portions engaging said second locating portions -26to thereby form a single longitudinal run of self-supporting shuttering.

56. A method according to claim 5 1, wherein the shutter components are assembled such that abutted pairs of ends of said lower wall shutter components are 5 not vertically aligned with abutted pairs of ends of said base shutter components.

57. A method according to claim 55 or 56, wherein the shutter components are assembled such that abutted pairs of ends of said lower wall shutter components are not vertically aligned with abutted pairs of ends of said upper wall 10 shutter components.

58. A method of casting a beam comprising assembling a self-supporting shuttering using the method of assembling claimed in any one of claims 45 to 57, and further comprising a step of casting concrete in said mould. 15 59. A method of making a raft foundation comprising casting a beam using the method of claim 58, further comprising also casting concrete above the mould in an enclosure, at least part of said enclosure being formed by a said wall 20 shutter component.

60. A system for assembly into a self-supporting shuttering for the casting therein of a beam substantially as hereinbefore described with reference to and as illustrated in Figures I to 4. 25 61. A method of assembling a self-supporting shuttering for the casting therein of a beam substantially as hereinbefore described with reference to and as illustrated in Figures I to 4.

62.A self-supporting shuttering for the casting therein of a beam substantially as hereinbefore described with reference to and as illustrated in Figures 1 to 4.

Amendments to the claims have been filed as follows CLAIMS 1 A system for assembly into a self-supporting shuttering for the casting thereagainst of a beam, the system comprising a base shutter component, a lower wall shutter component and an upper wall shutter component the lower wall shutter component being provided with first and second locating portions, the base shutter component being provided with a third locating , portion and the upper wall shutter component being provided with a fourth locating portion, whereby the first and third ZD 0 locating portions are engageable to locate the lower wall shutter component on the base shutter component when the lower wall shutter component is assembled on the base shutter component and the second and fourth locating portions are engageable to locate the upper wall shutter component on the lower wall shutter component when the upper wall shutter component is assembled on the lower wall shutter component, whereby the assembled shutter components form the self-supporting shuttering and wherein the first and third locating portions are adapted, when engaged, to lock said lower wall shutter component to said base shutter component and to resist any tendencies, occasioned by the action of casting the beam, of the lower wall shutter component to pivot relative to the base shutter component about the line of their engaged locating portions and of the lower wall shutter component to move upwardly relative to the base shutter component.

2. A system according to claim 1, wherein said upper wall shutter component is provided with supporting means for supporting a top wall shutter component.

3. A system according to claim 2, further comprising a said top wall shutter component, said top wall shutter component being provided with means for cooperating with the supporting means, to enable the top wall shutter component to be assembled on the upper wall shutter component to extend the height of the self- supporting shuttering 01 4. A system according to claim 3, wherein said top wall shutter component is a metal sheet.

5. A system according to claim 2, 3 or 4, wherein said means for supporting is a recess provided in a surface of said upper wall shutter component that will be upwardly facing when said self-supporting shuttering is assembled.

6. A system according to any one of claims I to 5, wherein said upper wall shutter component has a generally longitudinal upwardly facing surface along which a course of bricks can be laid when said shuttering is assembled.

7. A system according to any one of claims I to 6, wherein said system comprises a plurality of each of said three shutter components, suitable for assembly together to form a longitudinal run of self-supporting shuttering.

8. A self-supporting shuttering for the casting thereagainst of a beam, said self-supporting shuttering comprising: a lower wall shutter component provided with first and second locating portions; a base shutter component provided with a third locating portion; and an upper wall shutter component provided with a fourth locating portion; wherein -said lower wall shutter component is located on said base shutter component by engagement of said first and tbird locating portions; and said upper wall shutter component is located on said lower wall shutter component by engagement of said second and fourth locating portions and wherein the engaged first and third locating portions lock said lower wall shutter component to said base shutter component and resist any tendencies, occasioned by the action of casting the beam, of the lower wall shutter component to pivot relative to the base shutter component about the line of their engaged locating portions and of the lower wall shutter component to move upwardly relative to the base shutter component.

9. A system or self-supporting shuttering according to any one of the preceding claims, wherein upwardly facing surfaces of said upper and lower wall shutter components are elongate and the width of the upwardly facing surface of said upper wall shutter component in a direction perpendicular to the elongate direction thereto is larger than the width of the upwardly facing surface of said lower wall shutter component in a direction perpendicular to the elongate direction thereto when said self-supporting shuttering is assembled.

10. A system or self-supporting shuttering according to any one of the preceding claims, wherein said lower wall portion is a generally elongate slab, with the first and second locating portions being provided on opposite longitudinal edges respectively.

11. A system or self-supporting shuttering according to any one of the preceding claims, wherein said base shutter component is slab shaped and said third locating portion is adjacent an edge on a slab face.

12. A system or self-supporting shuttering according to any one of the preceding claims, wherein the first and third locating portions are adapted, when engaged, to resist the tendency of lower wall shutter component to move laterally relative to the base shutter component occasioned by the action of casting the beam.

13. A system or self-supporting shuttering according to any one of the preceding claims, wherein the second and fourth locating portions are adapted, when en aged, to resist the tendency of the upper wall shutter component to move laterally 9 '= relative to the lower wall shutter component occasioned by the action of casting the ID beam.

14. A system or self-supporting shuttering according to any one of the preceding claims, wherein said first and third locating portions allow, when engaged, 30 relative rotation in one direction only of said lower wall component to said base 31 component.

15. A system or self-supporting shuttering according to any one of the preceding claims, wherein said third locating portion comprises a recess and a lip protruding laterally into said recess and said first locating portion comprises a lipreceiving recess for receiving said lip when said first and third locating portions are engaged.

16. A system or self-supporting shuttering according to claim 15, wherein the protrusion of said lip into said recess causes the lip to overhang the base of the recess.

17. A system or self-supporting shuttering according to any one of the preceding claims, wherein said second and fourth locating portions are adapted, when engaged, to lock said upper wall shutter component to said lower wall shutter component.

18. A system or self-supporting shuttering according to claim 17, wherein said second locating portion comprises a laterally protruding lip and said fourth locating portion comprises a lip-receiving lateral recess for receiving said laterally protruding lip when said second and fourth locating portions are engaged.

19. A system or self-supporting shuttering according to claim 17 or claim 18, wherein, when said self-supporting shuttering is assembled, the portion of said upper wall shutter component forming said fourth locating portion extends down an inner face of said lower wall shutter component to overhang the base shutter component.

20. A system or self-supporting shuttering according to anyone of the preceding claims, wherein each of said three shutter components weighs less than 50 3el, Kg.

21. A self-supporting shuttering according to claim 8, or any one of claims 9 to 20, when dependent from claim 8, further comprising a top wall shutter component, wherein said upper wall shutter component is provided with supporting means for supporting said top wall shutter component and said top wall shutter component is assembled on said upper wall shutter component and supported by said supporting means to extend the height of the self-supporting shuttering.

22. A self-supporting shuttering according claim 8 or claim 21, or any one of claims 9 to 20 when dependent from claim 8, wherein a course of bricks is laid on an upper surface of said upper wall shutter component.

23. A self-supporting shuttering according to claim 21, wherein a course of bricks is laid along an upper surface of said upwardly facin',',, wall shutter component alongside sai4 top wall shutter component thereby forming a cavity between said top wall shutter component and said course of bricks.

24. A self-supporting shuttering according to any one of claims 8 or 21 to 23, or any one of claims 9 to 20 when dependent from claim 8, wherein said lower wall shutter component has a laterally facing surface which is generally perpendicular to an upwardly facing surface of said base shutter component, 25. A self-supporting shuttering according to any one of claims 8 or 21 and 24, or any one of claims 9 to 20 when dependent from claim 8, wherein said self-supporting shuttering comprises a plurality of each of said lower wall shutter I - component, said base shutter component and said upper wall shutter component.

26. A self-supporting shuttering according to claim 25, wherein said base3 )0 shutter components are assembled to abut each other end to end and lie in a first substantially horizontal plane with their third locating portions generally aligned, said lower wall shutter components are assembled on said base shutter components to abut each other end to end with their first locating portions engaging the third locating portions, and said upper wall shutter components are assembled on said lower wall shutter components to abut each other end to end with their fourth locating portions engaging said second locating portions.

27. A self-supporting shuttering according to claim 26, wherein abutted pairs of ends of the lower wall shutter components are not vertically aligned with abutted pairs of ends of the upper wall shutter components.

28. A self-supporting shuttering according to claim 26 or claim 27, wherein abutted pairs of ends of the lower wall shutter components are not vertically aligned with abutted pars of ends of the base shutter components.

29. A self-supporting shuttering according to any one of claims 8 or 21 to 28, or any one of claims 9 to 20 when dependent from claim 8, wherein in said selfsupporting shuttering is positioned in a trench, whereby a side of said trench, an upwardly facing surface of said base component and laterally facing surfaces of said lower and upper wall shutter components define a mould having a generally Ushaped cross-section for the casting therein of said beam.

30. A self-supporting shuttering according to claim 29, wherein the upwardly facing surface of said upper wall shutter component is below the level of an edge of said trench.

3 31. A self-supporting shuttering according to claim 29 or claim _)O, I wherein a damp-proof membrane is placed over the upwardly facing surface of said base component and the laterally facing surfaces of said lower and upper wall shutter 3 0 components.

32. A self-supporting shuttering according to any one of claims 29 to 3 1, wherein a beam is cast in said mould.

33. A self-supporting shuttering according to any one of claims 29 to 32, wherein said self-supporting shuttering acts as shuttering for at least part of a concrete edge beam of a raft foundation.

34. A self-supporting shuttering according to claim 33, wherein an upwardly facing surface of said raft foundation is generally level with the top of the self-supporting shuttering.

35. A foundation comprising a self-supporting shuttering according to any one of claims 8 or 21 to 34, or any one of claims 9 to 20 when dependent from claim 8.

36. A system or self-supporting shuttering according to any one of claims I to 34, wherein said base shutter component, said lower wall shutter component and sa-id upper wall shutter component are fabricated from concrete.

37. A system or self-supporting shuttering according to any one of claims I to 34, wherein said base shutter component, said lower wall shutter component and said upper wall shutter component are fabricated from a polymer based concrete.

38. A method of assembling a self-supporting shuttering for the casting thereagainst of a beam, the method comprising the steps of providing a lower wall shutter component with first and second locating portions; assembling said lower wall shutter component on a base shutter component by engaging said first locating portion with a third locating portion on said base component thereby to locate said lower wall shutter component on said base shutter component; and assembling an upper wall shutter component provided with a fourth locating portion on said lower shutter wall component by engaging said second locating portion with said fourth locating portion thereby to locate said upper wall shutter component on said lower wall shutter component; and wherein in the assembled shuttering the first and third locating portions lock said lower wall shutter component to said base shutter component and resist any tendencies, occasioned by the action of casting the beam, of the lower wall shutter component to pivot relative to the base shutter component about the line of their engaged locating portions and of the lower wall shutter component to move upwardly relative to the base shutter component.

39, A method according to claim 3 8, further comprising the step of assembling a top wall shutter component on said upper wall shutter component by engaging said top wall shutter component with said upper wall shutter component to thereby extend the height of the self-supporting shuttering.

40. A method according to claim 39, wherein said step of assembling said top wall shutter component comprises lowering said top wall shutter component into a recess provided on an upwardly facing surface of said upper wall shutter component.

41. A method according to any one of claims 38 to 40, wherein said step 0 of assembling said lower wall shutter component on said base shutter component comprises the steps ofplacing said first locating portion into a recess in said base shutter component wbLich forms said third locating portion whilst maintaining an acute ancrle between moulding faces of said lower wall shutter component and said base shutter component; and pivoting said lower wall shutter component relative to said base shutter component to increase the angle between the lower wall shutter component and the base shutter component to thereby engage in a lip-receiving recess of said first locating portion a lip protruding laterally into said recess of said third locating portion whereby to resist further pivoting of the lower wall shutter component 5 relative to the base shutter component.

42. A method according to any one of claims 3 8 to 4 1, wherein said second and fourth locating portions, when engaged, lock said upper wall shutter component to said lower wall shutter component.

43. A method according to claim 42, wherein said step of assembling an upper wall shutter component on said lower wall shutter component includes locking a laterally protruding lip which is part of said second locating portion into a lipreceiving lateral recess which forms part of said fourth locating portion whereby to resist the tendency for movement of said upper wall shutter component relative to said lower wall shutter component occasioned by the action of casting the beam.

44. A method according to any one of claims 3 8 to 43, further comprising the step of digging a trench in the ground and placing said base shutter component at the bottom of said trench prior to said assembling steps whereby a side of said trench, an upwardly facing surface of said base shutter component and laterally facing surfaces of said upper and lower wall shutter components define a mould having a generally U-shaped cross-section for the casting therein of said beam.

45. A method according to claim 44, further comprising the step of covering the upwardly facing surface of said base component and the laterally facing surfaces of said lower and upper wall components with a damp proof membrane.

46. A method according to any one of claims 38 to 45, further comprising the step of laying a course of bricks along an upwardly facing surface of said upper -3q- wall shutter -component.

47. A m ethod according to any one of claims 3 8 to 46, wherein a plurality of base shutter components are assembled to abut each other end to end and lie in a first substantially horizontal plane with their third locating portions generally aligned, a plurality of lower wall shutter components are assembled on said base shutter components to abut each other end to end with their first locating portions engaging said third locating portions, and a plurality of upper wall shutter components are assembled on said lower wall shutter components to abut each other end to end with their fourth locating portions engaging said second locating portions to thereby form a single longitudinal run of self- supporting shuttering.

48. A method according to claim 4-3), wherein the shutter components are assembled such that abutted pairs of ends of said lower wall shutter components are not vertically aligned with abutted pairs of ends of said base shutter components.

49. A method according to claim 47 or 48, wherein the shutter components are assembled such that abutted pairs of ends of said lower wall shutter components are not vertically aligned with abutted pairs of ends of said upper wall shutter components.

50. A method of casting a beam comprising assembling a self-supporting; shuttering using the method of assembling claimed in any one of claims 38 to 49, and further comprising a step of casting concrete in said mould.

51. A method of making a raft foundation comprising casting a beam using the method of claim 50, further comprising also casting concrete above the mould in an enclosure, at least part of said enclosure being formed by a said wall shutter component.

52. A system for assembly into a self-supporting shuttering for the casting therein of a beam substantially as hereinbefore described with reference to and as illustrated in the accompanying Figures.

53. A method of assembling a self-supporting shuttering for the casting therein of a beam substantially as hereinbefore described with reference to and as illustrated in the accompanying Figures.