GB2027089A

GB2027089A - Thermally Insulating Building Elements

Info

Publication number: GB2027089A
Application number: GB7926423A
Authority: GB
Original assignee: Telling Compaction Design & Re
Current assignee: Telling Compaction Design & Re
Priority date: 1978-08-03
Filing date: 1979-07-30
Publication date: 1980-02-13

Abstract

A building block (Fig. 2) or and roofing tiles (Fig. 4) the comprises a layer of thermally insulating materials on at least one surface of the building element. In one embodiment the building element consists of a body 4 of structural material comprising aggregate and a binder, and a surface layer of thermally insulating material comprising an expanded synthetic resin material such as polystyrene and a binder. The surface layer may be pre-formed and used as all or part of a mold for casting the body portion. The binder may be cement in each case and the block or tile formed by introducing the aggregate, polystyrene beads and cement into a mold which is then vibrated so that the polystyrene rises to the surface. Preferably the building element is shaped so that a plurality of elements can be laid to form a structure in which all joints between the edges of the elements are covered by thermally-resistant material. <IMAGE>

Description

SPECIFICATION Improvements in or Relating to Building Eiements This invention relates to building elements, for example, building blocks, bricks, and roofing tiles.

Because, inter alia, of the present day energy crisis and escalating heating costs, it is becoming increasingly important to build houses, business premises and like structures in a manner which will ensure that the minimum of heat is lost to the surroundings. This can be achieved to some extent, by for example, arranging insulating material in the roof of a building or in the cavity between the outer walls thereof. Although these methods are satisfactory to some extent, they still do not provide a full solution to the problem.

It is an object of the present invention to provide a building element having a relatively low thermal conductivity. It is a further object of the invention to provide a method of manufacturing such a building element, and it is yet another object of the invention to provide a building having walls and/or a roof structure of such elements.

From one aspect the invention consists in a building element having at least one layer of structural material and at least one layer of thermally-resistant material, wherein said structural material comprises aggregate and a binder, and said thermally-resistant material comprises an expanded synthetic resin material and a binder.

The term "aggregate" is used herein to define any reiatively coarse particulate load-bearing material such, for example, as gravel, crushed stones or slate, or brick, possibly together with a fine particulate material such as stone. The term "binder" is used herein to define any material capable of binding particles of the aggregate together to form a structural material and includes, for example, cement which, together with water, is used to bind particulate materials together to form concrete.

The expanded synthetic resin material may be, for example, expanded polystyrene, preferably in the form of granules, which may be generally spherical or of irregular shape.

Preferably the binder used to hold together the granules of synthetic resin material is the same as the binder used to hold together the particles of the aggregate. In this case, the building element may be manufactured by introducing all the materials into a mould which is then vibrated.

Since the synthetic resin granules are lighter than the aggregate particles, the granules will float to the top of the mould and form the layer of thermally-resistant material. Preferably building elements in accordance with this aspect of the invention are laid so that the layer of thermallyresistant material is vertical and, in particular, when building elements in accordance with the invention are used in double-skin walls, the thermally-resistant material of the building elements in each skin faces the cavity between the skins.

From another aspect the invention consists in a building element having at least one layer of structural material and at least one layer of thermally-resistant material, wherein the element is so shaped that a plurality of elements can be laid to form a structure in which all joints between the edges of the thermally-resistant layers are covered by thermally-resistant material.

From this aspect the invention also consits in a structure built from building elements, each having at least one layer of structural material, and at least one layer of thermally resistant material, the elements being so shaped and laid that any path for conduction of heat from one side of the structure to the other passes through at least one layer of thermally-resistant material.

A building element in accordance with this aspect of the invention includes at least one portion arranged to overlap a corresponding portion of an adjacent element. With this arrangement, the joint between the two adjacent elements is covered by the thermally-resistant layer of one of the overlapping portions so as to present a thermal barrier in the region of the joint.

It is to be understood that, if for example, normal rectangular building blocks are used with a thermally-resistant layer on the rear face thereof, there will be an interruption in the thermallyresistant layer at each vertical joint between adjacent blocks, and also at each horizontal joint between adjacent blocks. By providing overlapping portions in accordance with this aspect of the invention, these gaps in the thermally-resistant layer are avoided. In the case of building blocks, it is preferred that the elements should be arranged with two overlapping portions, one to cover the vertical joints, and one to cover the horizontal joints. In the case of a tile, on the other hand, it is only necessary to have the tiles overlapping at their side edges because the joints between the top and bottom edges of the tiles are covered by the usual overlapping row of tiles.

At the present time, most building blocks, bricks and tiles are produced in moulds and have to be left in their respective moulds for a considerable time while the materials set and cure. As a result, a large number of moulds are required, and it is an object of a further aspect of the invention to reduce the number of moulds required for a particular rate of production.

From this aspect the invention consists in a method of manufacturing a building element, wherein aggregate and a binder are introduced into a mould, at least a part of which consists of a thermally-resistant material and forms the outer layer of the finished element.

From this aspect the invention also consists in a building element having at least one layer of structural material and at least an outer layer of thermally-resistant material, wherein said outer layer forms at least a part of a mould in which the building element has been formed.

It is to be understood that the whole mould can consist of a synthetic resin material such as expanded polystyrene, and that the building element may be used with the whole of the mould in position on the element as an outer skin covering all surfaces of the element except the surface which was originally at the top when the materials were introduced into the mould.

Normally it will be found that the thermallyresistant material is strong enough to support the structural material while it is setting and curing.

However, it may be desirabie to reinforce the thermally-resistant material during the initial introduction of the structural materials into the mould. Thus the thermally-resistant material may initially form a mould lining which may be removed intact from the reinforcing mould as soon as the structural material has set sufficiently.

If it is required that the thermally-resistant material should not cover all the faces of the building element except one, parts of the mould may be formed by material other than thermallyresistant material, which parts are removed when the material has set. Thus, in the extreme case in which the thermally-resistant material is required on only one surface of the building element, the thermally-resistant material may form the base of the mould, and the remainder of the mould may be in the form of a metal or wooden frame. Even in such a case, it may be possible to remove the frame after the initial set of the structural material, and, in particular, without waiting for the structural material to cure.

Preferably the thermally-resistant material is provided with dowels or keys to lock the structural material to the thermally-resistant material.

It is to be understood that building elements in moulds of thermallyresistant material can be stacked directly into lorries or containers even before the materials have cured, said lorries or containers being provided with heating or air conditioning systems to effect the required curing, possibly during transport.

Since it is unneccessary to remove building elements in accordance with this aspect of the invention from their moulds, much more intricate designs can be formed than in the case of elements produced in conventional moulds which have to be designed so that the builing elements can be removed from them. In particular, building blocks or bricks can be formed to give interlocking thermal insulation. It is also possible for building blocks or bricks to be made more accurately than those made in conventional moulds and, if desired, the building elements can be bonded with adhesives.

Tiles formed with at least a base or underside of thermally-resistant material would be likely to be far less vulnerable than existing tiles. The thermally-resistant base would also facilitate fitting the tiles to battens made of synthetic resin material. Finally, a surface of synthetic resin material would provide a better weathering lock.

If desired, a building element in accordance with any of the aspects of the invention may be provided with one or more tongues or grooves extending along the upper surface of the element, the lower surface of the element being provided with one or more mating grooves or tongues.

Thus one building element can be placed on top of an underlying building element and be secured thereto in the manner of a tongue and groove joint. If desired, such elements can be secured together by means of adhesive in place of the usual mortar. It is, of course, to be understood that elements intended for the lowest course of a wall or like structure may have plain lower surfaces and similarly, if desired, building elements intended for the top course of a wall may have a plain upper surface.

In the manufacture of a building block, brick or tile according to the invention, a mould having a plurality of channels extending along one side thereof and a corresponding plurality of parallel recesses extending along the opposite side thereof may be filled to approximately one quarter of its volume with a slurried mixture of aggregate and binder such as cement. A further mixture of binder and expanded synthetic resin material such as expanded polystyrene chips or spheres is then charged to the mould until the mould is full. The mould is then vibrated causing the expanded synthetic resin material to rise to the surface and form a thermally-resistant shield on one surface of the element.

If the building element is a facing brick, the side of the element which is to face outwardly in the finished structure may be given a smooth and glossy finish by placing a sheet of polythene or glass at the bottom of the mould. Similar action may be taken if desired to give the upper surface of a roofing tile a smooth and glossy finish.

In an alternative method of manufacturing a building element in accordance with the invention, a mixture of aggregate, binder and expanded synthetic resin material is extruded by means of a compactor. The aperture through which the mixture is extruded is shaped in accordance with the desired configuration of the finished element. The extruded material is preferably deposited on a moving bed and conveyed through a heated tunnel to accelerate setting of the mixture. The mixture may be extruded in discrete quantities as required for the formation of individual blocks, bricks or tiles, or it may be extruded in a continuous length which is later cut into the individual elements.

Methods of performing the invention will now be described with reference to the accompanying diagrammatic drawings, in which: Figure 1 is a perspective view of a brick in accordance with the invention; Figure 2 is a perspective view of a building block in accordance with the invention; Figure 3 is a cross-sectional view of the block shown in Figure 2 on the line 3:3 looking in the direction of the arrows; Figure 4 is a perspective view of a roofing tile in accordance with the invention; Figure 5 is a cross-sectional view of the tile shown in Figure 4 on the line 5:5 looking in the direction of the arrows; Figure 6 is a detail of a tile as illustrated in Figures 4 and 5 showing one form of keying; Figure 7 is a similar detail showing an alternative form of keying; and Figure 8 is a perspective view of a facing panel in accordance with the invention.

The brick illustrated in Figure 1 comprises a layer 1 of structural material and a layer 2 of thermally-resistant material. The structural material may consist, for example, of expanded polystyrene spheres bound together by cement.

As shown, the brick includes a conventional frog 3, but it is preferred that this frog should be replaced by a plurality of channels extending parallel to the length of the brick and adapted to receive corresponding ridges formed on the base of the brick.

The building block illustrated in Figure 2 includes structural material 4 and thermallyresistant material 5. The structural material which may be, for example, concrete is shaped to provide a forward portion 6 and a rearward portion 7. The rearward portion 7 overlaps the forward portion in the horizontal direction at 8, and in the vertical direction at 9. As shown, the thermally-resistant layer 5, which may consist, for example, of polystyrene chips in a cement binder, extends not only over the rear face 10 of the rearward portion 7 and the rear face 11 of the forward portion 6, including the lower marginal portion indicated at 21, but also over the end faces 12 and 13 of the rearward portion 7, and one of the end faces 14 of the forward portion 6.

As indicated by dashed lines 15, 16, 1 7 and 18, the thermally-resistant material may also extend over the upper surfaces of the forward and rearward portions, and also over the lower surfaces of both portions. However, in most instances, the thermally-resistant layer will be provided only on the rear surfaces 10, 11 and 21 of the two portions. As can be seen, the thermally-resistant layer is provided with a number of dowels such as that shown at 1 9 in Figure 2, and at 20 in Figure 3 to key the thermally-resistant layer to the structural layer.

It can be seen from Figure 2 that, if a further similar building block is placed to the lefthand side of the block illustrated in Figure 2, the gap between the lefthand end face of the forward portion of the block illustrated in Figure 2 and the righthand end face of the forward portion of the further block is covered by the thermally-resistant layer 10 on the back of the rearward portion of the block illustrated. Similarly, if another similar block were placed to the righthand side of the block illustrated in Figure 2, the gap between the righthand end face of the rearward portion of the block iliustrated in Figure 2 and the lefthand end face of the rearward portion of the further block would be covered by the thermall-resistant layer 11 on the rear of the forward portion of the block illustrated.

From Figure 3 is can be seen that, if a further block 22 similar to that illustrated in Figures 2 and 3 is placed above the block illustrated, the gap 23 between the front portions of the two blocks is covered by the layer 10 of the rearward portion of the lower block, while the gap 24 between the rearward portions of the two blocks is covered by the thermally-resistant layer on the marginal portion 21 of the upper block. Similar considerations apply to the joint between the block illustrated in full lines, and a further block 25.

It is, of course, to be understood that the joints such as those shown at 23 and 24 in Figure 3 will normally be filled by mortar. However, when all the faces except the forward face of the blocks are covered by thermally-resistant layers, it may be more convenient to secure the blocks together by means of a synthetic resin adhesive.

Figure 4 illustrates a roofing tile which has been produced by pouring a mixture of aggregate, cement and water into a mould consisting almost completely of expanded polystyrene 26. The remaining parts of the mould which are removable are required to define the free edge 27; the horizontal surface 28, and the vertical surface 29 of a rabbet down the righthand side of the tile.

The horizontal and vertical surfaces 30 and 31 of a corresponding rabbet down the lefthand side of the tile are formed by the polystyrene part of the mould. As can be seen, the polystryrene base of the mould is formed with keyways 32 and 33 extending across the width of the tile to bond the concrete to the mould. A side view of one particular keyway is shown in Figure 6, and an alternative construction is shown in Figure 7. As can be seen from Figure 5, when tiles as shown in Figure 4 are laid sideby-side, the breaks in the lower polystyrene skin as at 34 and 35 are covered respectively by the polystyrene at 36 and 37 on the underside of the lefthand rabbet of the respective tile.It is, of course, to be understood that tiles as shown in Figure 4 will be laid in overlapping rows in the vertical direction so that the gap between two verticaily adjacent tiles will always be covered by the polystyrene on the undersurface of the overlapping tile above it.

It is to be understood that the particular arrangement shown in Figure 4 is only an example of the possible ways in which the thermally-resistant material can be used as the mould for a structural element. For example, the whole mould could consist of thermally-resistant material, all of which is left in position in the finished article. Alternatively, the thermallyresistant material could form only one part of the mould.

When roofing tiles provided with insulating material in accordance with the invention are used for a pitched roof, the risk of condensation in the roof space itself is reduced. If a permeable insulation material is used, care should be taken to ensure that an effective vapour barrier is installed on the underside. It should be noted, however, that the roof space should not normally be ventilated to the outside.

Figure 8 illustrates a facing panel produced by partially filling a normal mould with a slurried mixture of aggregate and cement, followed by a further mixture of cement and expanded polystyrene chips, the mould being vibrated to cause the polystyrene chips to rise to the surface.

To give the outer side of the panel a glossy finish, a sheet of polythene or glass is placed at the bottom of the mould.

It will be seen that the panel illustrated includes an outer layer of concrete 41 and an inner layer of polystyrene 42. As in the case of the building brick illustrated in Figure 2, the panel includes a forward portion 43 and a rearward portion 44. The rearward portion 44 overlaps the forward portion 43 along a right-hand margin 45 and a lower margin 46. Similarly, the forward portion 43 overlaps the rearward portion 44 along a left-hand margin 47 and an upper margin 48. As shown, the polystyrene layer 42 extends only over the rear face of the rearward portion 44. However, it is to be uderstood that, if desired, the polystyrene may extend also over the rear faces of the overlapping margins 47 and 48. As in the case of the tile illustrated in Figure 4, the polystyrene is keyed to the concrete as at 49 and 50.

It is of course to be understood that, if desired, the lowest row of panels may be constructed without the overlapping margin 46 and the top row of panels may be constructed without the overlapping margin 48. Similarly, the extreme righthand column of panels may be constructed without the overlapping margin 45, and the extreme lefthand column of panels may be constructed without the overlapping margin 47.

Claims

1. A building element having at least one layer of structural material and at least one layer of thermally-resistant material, wherein said structural material comprises aggregate and a binder, and said thermally-resistant material comprises an expanded synthetic resin material and a binder

2. A building element as claimed in Claim 1, wherein said synthetic resin material is polystyrene.

3. A building element as claimed in Claim 1 or Claim 2, wherein said synthetic resin material is in the form of granules.

4. A building element as claimed in Claim 3, wherein said granules are substantially spherical.

5. A building element as claimed in any of the preceding Claims, wherein the binder in said layer of structural material is the same as the binder in said layer of thermally-resistant material.

6. A building element as claimed in Claim 5, wherein said binder is cement.

7. A building element as claimed in any of the preceding Claims wherein the thermally-resistant material is provided with a plurality of dowels or keys to lock the structural material to the thermally-resistant material.

8. A method of manufacturing a building element as claimed in any of the preceding Claims, wherein the aggregate, the synthetic resin material in particulate form, and the binder are introduced into a mould which is vibrated to cause the synthetic resin material to float to the top of the mould.

9. A building element having at least one layer of structural material and at least one layer of thermally-resistant material, wherein the element is so shaped that a plurality of elements can be laid to form a structure in which all joints between the edges of the thermally-resistant layers are covered by thermally-resistant material.

10. A building element as claimed in Claim 9, including at least one portion arranged to overlap a corresponding portion of an adjacent element.

11. A building element as claimed in Claim 10, provided with two overlapping portions, one to cover vertical joints between adjacent elements, and the other to cover horizontal joints between adjacent elements.

12. A building element as claimed in any of Claims 9 to 11, wherein said structural material comprises aggregate and a binder, and said thermally-resistant material comprises an expanded synthetic resin material and a binder.

13. A building element as claimed in Claim 12, wherein said sythetic resin material is polystyrene.

14. A building element as claimed in Claim 13, wherein said polystyrene is in granular form.

1 5. A building element as claimed in any of Claims 12 to 14, wherein the binder in said structural material is the same as the binder in said thermally-resistant material.

16. A building element as claimed in Claim 15, wherein said binder is cement.

17. A building element as claimed in any of Claims 9 to 16, wherein the thermally-resistant material is provided with a plurality of dowels or keys to lock the structural material to the thermally-resistant material.

1 8. A structure built from building elements, each having at least one layer of structural material, and at least one layer of thermallyresistant material, the elements being so shaped and laid that any path for conduction of heat from one side of the structure to the other passes through at least one layer of thermally-resistant material.

19. A structure as claimed in Claim 18, wherein said building elements are building blocks, and said structure is a wall.

20. A structure as claimed in Claim 18, wherein said elements are tiles, and said structure is a roof.

21. A method of manufacturing a building element, wherein aggregate and a binder are introduced into a mould, at least a part of which consists of a thermally-resistant material and forms the outer layer of the finished element.

22. A method as claimed in Claim 21, wherein the whole mould consists of a synthetic resin material.

23. A method as claimed in Claim 22, wherein said sythetic resin material is expanded polystyrene.

24. A method as claimed in any of Claims 21 to 23, wherein said mould is placed in a reinforcing support frame before the aggregate and binder are introduced therein, and is removed from said support frame as soon as the aggregate and binder have set sufficiently to make the building element self-supporting.

25. A method as claimed in Claim 21, wherein parts of the mould consist of thermally-resistant material and further parts, which are removable, consist of rigid material.

26. A method as claimed in Claim 25, wherein the base of the mould consists of a thermallyresistant material and the remainder of the mould is in the form of a removable frame.

27. A method as claimed in any of Claims 21 to 26, wherein the mould, or the part thereof which consists of thermally-resistant material, is provided with a plurality of dowels or keys to lock the aggregate and binder to the thermallyresistant material.

28. A building element having at least one layer of structural material, and at least an outer layer of thermally-resistant material, wherein said outer layer forms at least a part of a mould in which the building element has been formed.

29. A method of manufacturing a building element as claimed in any of Claims 1 to 7, or Claims 9 to 17, wherein a mixture of aggregate, binder and expanded synthetic resin material is extruded by means of a compactor.

30. A building element substantially as hereinbefore described with reference to, and as illustrated, in the accompanying diagrammatic drawings.

31. A method of manufacturing a building element substantially as hereinbefore described with reference to the accompanying diagrammatic drawings.

32. A structure built from a building element as claimed in Claim 30, or manufactured by a method as claimed in Claim 31.

33. Any features of novelty, taken singly or in combination, of the embodiments of the invention as hereinbefore described with reference to the accompanying diagrammatic drawings.