GB2254863A - Building panel. - Google Patents

Abstract

A building element comprises a pair of meshes (2) of support wires, foam insulation (AA) and a cavity for concrete between said meshes tied together by wires. In one form (A) for partition walls either or both meshes are arranged so that decorative material can be attached and in another form (B, C) for a structural wall the mesh is spaced from the slab and provides reinforcing rods for a coating of concrete. The elements can be prefabricated at a factory for subsequent coating in concrete or decorative materials on site. The important feature of the invention is that there are enough wires within the cavity for full reinforcement of the panel.

Description

BUILDING ELEMENTS The invention relates to building elements for use as cladding panels, partition walls, loadbearing walls, floor and roofs in the construction of buildings generally. The object of the present invention is to provide elements whereby the ease and simplicity of construction can be improved over existing systems.

A system is known from French Utility Model 2 566 818 which uses corrugated panels of foam polystyrene in conjunction with panels of mesh as a basis for a structural system where the concrete is applied on to the foam for various structural purposes.

The system however has a number of problems in practice and the present invention aims to overcome these problems. It aims to provide a system where units can be produced in a factory and then can be brought to a site and be erected with the minimum addition of extra reinforcing rods at the site. This allows for a more closely controlled and cost effective operation.

Accordingly, the invention provides a building element comprising a rigid slab of foam plastics heat insulating material having opposed parallel plain surfaces and a mesh panel of carrier wires on each said opposed surface and tied together through the slab.

With this arrangement the wires can be readily applied in sufficient quantity in a pre-installation factory operation.

In a first form of the invention to be used to form a partition wall the mesh panel of carrier wires comprises a plurality of support wires parallel to one another which when the panel is disposed vertically with the support wires horizontal can serve as a support on which to hang decorative cladding materials.

The number of wires and their size should be sufficient for the purpose as will be described later with reference to the described embodiment. Generally there will be relatively widely spaced horizontal carrier wires supported by more closely spaced vertical carrier wires. The support wires can also serve as a key for a layer of decorative plaster.

Thus an element is provided which can have a decorative layer - plaster, marble or tiles- attached to each side.

In a second form of the invention a pair of elements of the kind described as the first form can be tied together by tie combs formed of metal support rods, with a cavity between the two elements which can be filled with light weight concrete to encapsulate the tie combs. Such composite panels can then be capable of taking limited structural loads (up to two storeys height for example).

In a third form of the invention at least one of the mesh panels is spaced from its respective slab surface whereby when said surface is coated in concrete the mesh panel is fully encapsulated. The mesh can include sufficient reinforcing rods at the prefabrication stage to achieve the purpose of full reinforcement without the need for the addition of extra reinforcing rods at site. The specification of rods necessary for this purpose will be described later with reference to the described example.

The spacing of the mesh panel is preferably achieved by provision of one or more spacers of plastics material. Conveniently these may be grooved to assist location. In general, the use of a plain surface to the slab and the use of the spacer or spacers enables the whole of the mesh panel to be equidistant from its slab surface and so to be fully encapsulated in concrete. This contrasts with the prior art system previously referred to where the corrugations preclude this possibility.

In a fourth form of the invention a pair of elements of the kind described as the third form are tied together by tie combs formed of metal rods, so as to be spaced apart by an amount which defines a cavity between the two elements and with the spaced mesh panels of each element being within the cavity. Then when concrete is filled into the cavity each of these spaced mesh panels is encapsulated to form a composite structural panel capable of taking high structural loads such as would be encountered in a multi-storey building.

In a fifth form of the invention an element is formed by a combination of an element of the kind defined as the third form in conjunction with rigid blocks of plastics foam material. Such an element can be laid flat and have concrete applied which encapsulates the spaced mesh panel and provides a floor or roof panel.

In an overall structure of a building the elements in the various forms of the invention will be tied together, and concrete and other materials will be applied after which a rigid decorated structure is achieved.

The materials employed in the invention can include: 1. A plain faced slab of CFC free, water-resistant, flame-retardant grade of expanded polystyrene with a density of 26Kg per cubic metre and a thickness of 40mm between the plain parallel faces.

2. Various lattices and combs of electrically welded zinc coated carbon steel.

3. Plastic spacer blocks.

4. A carrier of two opposing lattices spaced apart with plastic spacer blocks and various reinforcement bars according to duty for use as beams in floors and roofs.

5. Blocks of polystyrene as described at (1) employed as formers to create the voids for the beams described at (4), where the reference numerals refer to the examples to be described.

The elements of the invention employing the above materials can be: A. A single panel incorporating materials (1) and (2) for use as a cladding panel, a partition wall and a permanent shuttering for floors and roofs.

(Fig. 1) (the said first form of the invention) B. An element comprising two panels of type A pre fabricated to provide a cavity of 50mm between the inner faces of the panels for use as permanent shuttering for plain lightweight concrete load bearing walls in buildings up to two storeys high.

(Fig. 2) (the said second form of the invention) C. An element comprising two panels AA which are a variation of panel type A together with spacer cradles and prefabricated to provide cavities of various widths between the inner faces of the panels for use as permanent shuttering embodying the reinforcement necessary for the construction of reinforced concrete walls, where function demands and in multi-storey buildings. (Fig. 3) (the said fourth form of the invention utilising a pair of elements in accordance with the third form of the invention).

D. An element comprising a panel of polystyrene 40mm thick with a lattice (2) on one face only and on the other face two assemblies (4) at 600mm centres for use as the permanent shuttering and steel reinforcement for floors and roofs of reinforced concrete construction. (Fig. 9) (the said fifth form of the invention).

The invention enables standard materials to be brought together in a specific manner and under individual factory controlled conditions, which can then be employed in construction in their prefabricated form to achieve performance results not previously available in this simple form.

In all applications the elements can be light and easy to manhandle, obviating the need for mechanical handling plant except for lifting to level of use in multi-storey constructions. They are easy to cut to facilitate the formation of openings (such as doors and windows).

In all applications the elements can provide thermal and acoustic insulating as an integral feature.

The thermal insulation qualities can be utilised to avoid surface condensation.

A homogenous nature can be achieved in the finished surfaces which obviates shrinkage and surface cracking particularly at internal angles of walls with floors which is the most common incidence of cracking in most structures.

The finished structure employing the elements can have a monolithic nature which is effective in areas of seismic activity and even the partition walls can add to the stability of the structure in this respect.

The whole structure can be proof against progressive collapse.

In the particular case where the elements are used for reinforced concrete construction, the design enables the compressive strength of concrete to be achieved in seven days instead of twenty-eight days as with traditional methods and work can be carried out in extreme climates without the need for traditional protective methods against cold and heat, provided only that the ambient temperatures encountered allow the operation of the pump for placing the concrete.

In particular the enveloping panels of element C can provide the insulation whereby the concrete which is poured into the cavity between these panels achieves its design strength more quickly than in the uninsulated cavity provided by traditional shuttering, and consequently floors and upper storey walls can proceed far sooner.

Furthermore, because of the design where the reinforcing steel does not provide an obstacle to the easy placement of concrete, the concrete can be of a specially formulated mix with a small aggregate which obviates the need for vibration necessary with traditional methods.

Also in the case of reinforced concrete walls the on site operations can be reduced to standing the elements in position, minimal tying together of adjacent units and considerably less temporary support of the elements (only needed to prevent bulging when the concrete is placed) than the strutting and waling employed in traditional construction. This can result in a system whereby a reinforced concrete structure is achieved 77% faster than by traditional methods.

Another advantage of the system is that services can be housed within the thickness of the polystyrene panels by simply melting out the polystyrene with a hot air gun. This process is far quicker than the need to chase solid structures or drill timber structures.

Thereafter walls and ceilings can be finished by plastering or rendering and in particular other forms of sheet material finishes such as stone and marble can be applied to walls by hooking directly to the horizontal carrier bars.

Therefore factory made units according to the invention can incorporate all the necessary functions of the elements of construction in one piece, so that one site operation provides permanent shuttering, thermal and acoustic insulation, integral reinforcement, integral key or support system for facing integral protection of concrete whilst curing, all of which lead to greatly reduced time and cost on site.

Factory production of the elements provides accuracy and highly economic use of materials leading to lightweight, speed of erection, and eventual construction costs far below those of traditional methods.

In particular for reinforced concrete walls the design enables all the necessary reinforcement to be incorporated as an integral part of the element which, because its size has been precalculated and the bars are already held within the cavity and properly spaced to facilitate concrete cover, avoids any waste and also provides a structural strength formerly only achieved by greater quantities of steel reinforcement and its time consuming assembly.

The design further enables full shuttering qualities to be achieved from polystyrene instead of the expensive materials used traditionally, namely timber or steel and in the case of timber the inherent waste of a valuable raw material.

An embodiment of the invention will now be described by way of example with reference to the accompanying diagrammatic drawings in which: Figure 1 shows a vertical cross-section of the single panel A (for cladding, partitions etc).

Figure 2 shows a vertical cross-section of the double panel B employing two single panels A (for two storeys etc).

Figure 3 shows a vertical cross-section of a double panel C employing two single panels AA (for multi-storey work).

Figure 4 shows the form of lattice work (2) attached to the surfaces of each of the elements A and B and the outer surfaces of element C.

Figure 5 shows an isometric projection part broken away of two structural elements tied together for the pouring in of concrete.

Figure 6 shows a horizontal cross-section of the Figure 5 arrangement.

Figure 7 shows a horizontal cross-section of the Figure 2 arrangement.

Figure 8 shows an isometric projection of element D for use in floors and roofs.

Figure 9 shows a horizontal cross-section of a finished floor or roof element D.

Referring to Figure 1, an element A comprises a rigid slab of CFC free, water repellant, flame retardant expanded polystyrene of a density of 26Kg per cubic metre, a thickness of 40mm and having opposing parallel plain faces (1), lattice works of electrically welded zinc coated steel wire (2) on and in contact with each face of the polystyrene slab to provide a key for plaster and/or rendering. The two lattices are connected through the polystyrene by zinc coated steel ties (8) which are electrically welded to the opposing lattices. (First form of the invention).

Referring to Figure 2, a double panel B for load bearing walls of plain lightweight concrete for use in structures up to two storeys in height employs two of the same elements A which are tied together and spaced apart by zinc coated steel combs (2b) which are electrically welded to each of the opposing lattices on the cavity faces of the polystyrene. (Second form of the invention).

Referring to Figure 3, a double panel C for reinforced concrete walls employs the same polystyrene panels (1) and two of the same lattices on each outer face as used in element A together with lattices of varying size vertical bars (2a) which are spaced off by plastic cradles (3) but parallel to the inner faces of the polystyrene slabs. (Fourth form of the invention incorporating two of the third form of the invention).

The lattices (2a) are spaced off the face of the polystyrene by means of plastic spacer cradles (3) (see Figure 5) 25mm thick which permit full encasement of the steel by concrete when it is subsequently poured in. These cradles (3) have grooves to receive the horizontal and vertical steel bars to ensure perfect alignment.

Lattices (2a) are tied together and spaced apart by zinc coated steel combs (2c) thus connecting the panels AA.

The primary steel reinforcement (6) {the vertical bars (6) of lattices (2a)} are selected by manufacturing software (a computer programme to perform structural calculations) according to the structural duty to be performed by the panel.

The following table shows the bar sizes employed for primary reinforcement in walls derived from the requirements of the British Standard Code of Practice for the design of reinforced concrete structures.

Column 2 shows the standard to be met and column 3 shows the bar sizes employed to meet this standard.

The unusual and beneficial aspect of the design is the small diameter of bars which can be used because of the invention.

TABLE 1 1 2 3 4 Thickness of Area of primary Diameter Area of primary concrete core (vertical) re- of bar bars in double to be rein- inforcement to at 50mm panel (42 in number) forced in mm comply with pitch in in mm2/m B.S.C.P 8110 in mm length of wall mm2 length of wall 100 400 3.5 404 150 600 4.5 667 200 800 5.0 825 250 1000 6.0 1187 Column 4 shows that the primary steel in all lattices exceeds the requirement of the British Standard.

The width of the cavity "x" between the internal faces of the opposing panels of polystyrene is selected by the manufacturing software according (i) to the structural duty to be performed by the wall and, (ii) by the acoustic performance required of the wall.

For the partition wall panel A the lattice work of zinc coated steel wires (2) to form the cladding or plaster support should consist of vertical wires of 2.5mm diameter spaced so that 17 wires occur in a 1.2 metre span; while the horizontal wires are of 3.5mm diameter and 17 wires occur in a 2.7 metre span; giving a pitch of 75mm in the vertical wires and a pitch of 166.66mm in the horizontal wires.

For each spaced structural lattice to be used in the structural element of Figure 3 the specification of the wires depends on the load to be carried as follows: Vertical No. in Pitch Wires 1.2m (mm) width 3.5 25 50 4.5 25 50 5.0 25 50 6.0 25 50 Horizontal No. in Pitch Wires 2.7m (mm) length 3.5 19 150 3.5 19 150 3.5 19 150 3.5 19 150 For the cross ties 8 there should be at least 17 cross ties of 3.5mm diameter in any given 1 square metre area, approximately uniformly located across the area.

Prior to concreting adjacent wall panels are connected by stapling (7) together the end vertical bars in each panel. At this stage the structure should be strapped with walings (not shown) until the concrete has set and can retain its own shape without bulging (10).

With the addition of specially designed starter steel and heavier gauge latticeworks retaining wall performance can also be achieved.

Referring to Figures 8 and 9, here element D is manufactured comprising a single panel of polystyrene 40mm thick having a lattice (2) over the whole of one face only and over lesser areas of the other face two assemblies (4) at 600mm centres. Each assembly (4) has two opposing lattices spaced apart by plastic cradles (3) and includes a number of parallel reinforcement bars (11) in accordance with the required span and load. For a span up to 4 metres, 6 bars are needed at 6mm diameter, up to 5 metres, 8 bars at 6mm diameter and up to 6 metres, 8 bars at 8mm diameter or 10 bars at 7mm diameter. This then provides the permanent shuttering and reinforcement for floors and roofs.

The amount of reinforcement (11) in assembly (4) is selected by the manufacturing software to meet with the load span criteria given by the user.

The units are delivered to site numbered according to location which is identified on a placement plan.

Blocks of dense polystyrene (5) for use as formers to create the voids to be filled with concrete are included in the delivery.

To create a floor then, the composite unit D is propped in position at the desired elevation, using any proprietary propping system. Because of the eventual light weight of the finished floor, fewer props are needed than with traditional reinforced concrete floors. Projecting reinforcing rods (11) of assembly (4) are interlaced with vertical rods (6) of the lattice (2a) in the wall shown in Figure 5.

Loose horizontal bars (not shown) are threaded into position perpendicular to the projecting rods (11) of the triangular assemblies (4) to tie the roof or floor and wall steel structure together. This process is also adopted for tying the walls to the floors and roofs when employing element B for walls.

Starter bars for the next level of reinforced walls are also incorporated at this stage.

The polystyrene blocks (5) are laid in position at 600mm centres on element D and the resulting voids are filled with concrete. A loose steel mesh (9) is then laid over the whole surface area of the floor spaced off the polystyrene blocks (5) with spacer cradles (3) and covered with a 50mm layer (10) of structural topping concrete.

In summary the system combines numerous operations previously only achieved by several trades so that walls and floors can be erected with far fewer stages and achieve at one time the placement of shuttering, reinforcement steel, acoustic and thermal insulation, a key and or support system for the surface finishes, faster ultimate strength achievement, avoidance of waste, avoidance of chasing solid materials for service routes, avoidance of condensation, freedom from shrinkage and cracking, and the consequent speed and cost economies which derive from these features.

Claims (12)

1. A building element for use in the construction of a building comprising a rigid slab of foam plastics heat insulating material having opposed plain parallel surfaces and a mesh panel of carrier wires on each said opposed surface and tied together through the slab.

2. A building element according to claim 1 in which the mesh panel on at least one side of the slab comprises a plurality of support wires parallel to one another which when the panel is disposed vertically with the support wires horizontal the support wires can serve as a support on which to hang decorative cladding materials.

3. A building element according to claim 2 comprising a mesh panel on each side of the slab comprising parallel support wires to form horizontal supports for decorative cladding materials or plasterwork so as to define an element for formation of a partition wall.

4. A building element comprising a pair of elements according to claim 2 or claim 3 which are tied together by transverse cross wires so that the elements are parallel and define a cavity therebetween, whereby the cavity can receive lightweight concrete for formation of a structural support wall encapsulating and reinforced by said transverse cross wires.

5. A building element according to claim 1 or claim 2 having on one surface a spaced panel of reinforcing wires whereby when said surface is coated with concrete said reinforcing wires will be encapsulated so as to provide a structural support wall.

6. A building element according to claim 5 comprising at least one spacer of plastics material which is arranged to maintain the spaced panel equidistant from and parallel to its respective slab surface.

7. A building element according to claim 6 in which the or each spacer is grooved for location with respect to its panel of reinforcing wires.

8. A building element comprising a pair of building elements according to any one of claims 5 to 7 which are tied together by transverse cross wires so that the elements are parallel and define a cavity therebetween with the respective spaced panel of reinforcing wires of each element located within said cavity, whereby the cavity can receive concrete for formation of a structural support wall encapsulating and reinforced by the reinforcing wires of each spaced element and the transverse cross wires.

9. A building element comprising a composite of at least one element according to claims 5 to 7 in combination with one or more blocks of rigid foam material and arranged to serve as the basis for a structural floor or roof panel when coated with concrete.

10. A building element substantially as herein described with reference to any one or more of the accompanying diagrammatic drawings.

11. A wall or floor or roof panel comprising a building element according to any one of the preceding claims and carrying a layer of decorative material such as plaster or tiles or rendering, or a coating of concrete on either or both sides.

12. A building comprising a plurality of panels according to claim 11 held together by the carrier wires being embedded in a coating of set concrete.