IMPROVEMENTS IN/OR RELATING TO INSULATED CONSTRUCTION
PANELS AND/OR METHODS OF MANUFACTURING SUCH PANELS
AND/OR METHODS OF CONSTRUCTION USING SUCH PANELS
This invention relates to insulated construction panels and/or methods of manufacturing such panels and/or methods of construction using such panels. Insulated construction panels according to the present invention are very suitable for low cost residential and light commercial constructions. They have particular application in erecting typhoon proof dwellings or community buildings. Strength and comparative low cost, coupled with a method of manufacture which can be adapted to suit local conditions and use some local materials, is available with the present invention.
Accordingly in one aspect the invention consists in a method of manufacturing an insulated construction panel, said method comprising the steps of laying down in a horizontal or substantially horizontal mould a layer of cementitious material reinforced with reinforcing fibre means, placing on the formed layer preformed insulating material with the periphery of the insulating material inside the periphery of the mould but extending to insulate a substantial part of the panel while leaving free of insulation a structural section at each end of the mould and completing the panel by placing in the mould further cementitious material reinforced with reinforcing fibres to embed the insulating material, form a layer of reinforced cementitious material over the insulating material and complete the structural sections at each end of the panel. In a further aspect the invention consists in an insulating construction panel comprising an outside wythe of cementitious material reinforced with reinforcing fibre means, a layer of insulating material with the periphery of the insulating material located inside the periphery of said panel but extending to insulate a substantial part of said panel while leaving free of insulation a structural section at each end of said panel and an inside wythe of reinforced cementitious material with the outside and inside wythes joined together with reinforced cementitious material to complete the structural sections at each end of the panel.
In a yet further aspect the invention consists in a method of construction using insulated construction panels according to the preceding paragraph, said method comprising the steps of forming a building profile, forming panel support footing means below existing ground level in accordance with said building profile, supporting and levelling the panels on said footing means to form wall sections of
the building, pouring a concrete floor tied to the erected panels to join the base of the erected panels together, fixing connecting means to join the tops of the erected panels together, and supporting a roof structure from the top of said connected panels. One preferred form of the invention in its various aspects will now be described with reference to the accompanying drawings in which:
Figure 1 is a partly diagrammatic front view of a construction panel according to the present invention;
Figure 2 is a transverse cross-section through Figure 1; Figure 3 is a detail of the side section of Figure 1;
Figure 4 is a detail of the top part of Figure 1; Figure 5 is a detail of the bottom part of Figure 1; Figure 6 is an illustration of steel fibre reinforcement; Figure 7 is a section through a building erected using the construction panels and building methods herein described;
Figure 8 is a section through the building detailing a louvre panel infill between construction panels according to the present invention;
Figure 9 is a detail showing the connection between the top of the construction panels and a roof section; Figure 10 is a comer detail showing the top of construction panels joined at the corner; and
Figure 11 is a section through such a corner joint.
Formation of an insulated construction panel 1 requires a mould having a mould cavity within which the panel is formed. Form work can be used to provide the mould or a purpose built mould could be employed. The mould for the panel is assembled on a horizontal or substantially horizontal surface.
The panel is formed using a suitable cementitious material. The material could be selected from that locally available but in the preferred embodiment would ordinarily use concrete formed using Portland cement and a suitable mix of aggregates. Local material would normally be employed in forming the mix of aggregates.
The cementitious material such as the concrete aggregate has mixed in with it reinforcing fibre means. Again, these reinforcing fibre means could be selected from locally available product, for example natural fibres, such as coconut husk fibres. A structurally stronger panel is produced using steel fibre reinforcement such as XOREX (trade mark) steel fibre reinforcement. An example of such steel fibre reinforcement is illustrated in Figure 6. The steel fibre is made from
flattened mild carbon cold drum steel wire bent in a crimped configuration as illustrated to provide enhanced mechanical bonding. When mixed in with the concrete, the steel fibres disperse evenly in the concrete. The high tensile strength, the ease of handling and mixing, and the uniform distribution make this steel fibre reinforcing particularly suitable. The fibre length can be from 25 mm to 63 mm with 40 mm to 50 mm being most suitable.
Depending upon the strength characteristics of the construction panel, other fibre reinforcing means could be used such as suitable plastics material or glass fibres. Using reinforcing fibre means allows the reinforcing to be mixed in with the cementitious material so that when this mixed material is poured in the mould it is already reinforced.
In broad terms the panel 1 has a first layer of cementitious material 2 placed in the mould. The reinforced cementitious material is compacted, for example by vibration, and an insulating slab 3 (preferably a polystyrene slab) is placed on the layer 2. The slab is of a size such that it insulates a substantial portion of the panel but leaves structural sections 4 and 5 at the ends of the panel. The structural section 4 provides a lintel and the structural section 5 a reinforced base portion of the panel. Preferably the insulation 3 is stopped short of the side edges 6 so that there is a strip 7 of cementitious material along the side edge of the panel. The periphery of the polystyrene slab is illustrated by dotted outline in Figure 1.
To increase the structural strength it is desirable to include reinforcing rods in the end sections 4 and 5 and connecting rods down the side sections 7. The reinforcing rods 8 are bent and joined together using reinforcing tying to complete a reinforcing profile as is illustrated in Figure 1.
It is desirable to have socket connectors in the top edge 9 of the panel. The socket connectors 10 are preferably provided by TCM12 concrete inserts. The head 11 of the insert has an aperture through which a reinforcing rod can pass and be tied to the reinforcing rod 8.
Socket connectors 11 are also formed extending in from the inside bottom face of the panel. These socket connectors 11 are also preferably TCM12 connectors fixed to the reinforcing rods 8 in a like manner to that previously described. In the construction of the panel, once the reinforced cementitious layer 2 has been placed in the mould, the insulating material can be laid on the placed cementitious material and the reinforcing rods and sockets placed in position.
The panel is completed by pouring more cementitious material in the mould to form the top face 12 and complete the connecting structural sections at each end and the cover sections down the sides of the panel. This cementitious material is also vibrated or otherwise appropriately compacted to give an acceptable finish. It will be appreciated that using the methods as previously described, panels of different dimensions can easily be formed. The insulating slab can have a thickness of between 30 mm and 150 mm, with the preferred thickness being substantially 50 mm. The concrete containing the reinforcing fibres provides a cover over the insulating material of between 20 mm to 50 mm on each side and fills the structural sections at each end and the cover sections down the side of the panel. The preferred cover is approximately 40 mm but it will be appreciated that these are given as illustrative figures and could be varied depending upon the strength parameters and characteristics of the materials being employed in the construction of the panels. The overall dimensions of the panels can also be varied but it should be recognised that the panels are comparatively heavy and therefore for relative ease of handling should not be made too large. A panel having an overall width of 1100 mm and an overall height of 2900 mm is a useful size for completing dwellings and community buildings that are typhoon proof. The panels once they have been formed in the mould and allowed to set are then removed from the mould. The completed panels thus have an inside and outside layer or wythe of reinforced cementitious material covering the core of insulating material 3 and with the structural sections at the top and bottom of the panel. It is desirable to cure the panels while standing on one edge. The panels can be handled using a lifting frame or connecting lifting stirrups using the threaded connector in the top edge of the panel.
The completed panels that have been cured to gain sufficient structural strength can be transported to a building site to erect a building. The building profile will have been marked out and support pads or footings 13 placed below the ground level 14. The panels 3 are supported on the footing 13 in an upright position and are braced and adjusted so that they are vertical and level. The inside connectors 11 have hooked threaded rods 15 connected thereto to tie in with reinforcing 16 used to reinforce a concrete floor 17.
The floor 17 is poured on a suitable prepared and compacted base with the required moisture membrane in position. The reinforced concrete floor 17 with the connectors 15 thus ensures that the base of the panels are tied together and
the panels held in the correct position. Suitable building services where required can be pre-laid before the floor is poured.
The top of the erected panels are connected using a connecting member, for example, an angled member 18. This member is bolted to the socket connectors 10 and structurally joins the tops of the panels together and will span any gap between panels. The member 18 is more clearly illustrated in the detail in Figure 9. The angled member 18 can have welded thereto connecting plates to tie in the roof structure. An upright plate 19 is shaped so that it engages over the rafter 20 and the rafter is bolted to the plate by a bolt passing through aperture 21. A flat plate 22, also welded to extend from the angle 18, provides a support for the perimeter baton 23. Once again, the baton can be held in place for example using a coach screw passing through the plate 22 and into the baton 23. This construction is very strong and allows a typhoon proof building to be erected using the construction panels as previously described. Any conventional roof structure can be fitted on the rafters 20 but preferably a designed roof truss is manufactured to suit the building. On the rafters 20 the purlins 24 can be fixed using lumber lock cyclone ties. The roof cladding is fixed to the purlins, again with suitable fastening consistent with producing a typhoon proof roofing 25. A gutter tray 26 is specially shaped and engages over a fascia 27 with a soffit lining 28 and baton 29 completing the roof detail.
The construction panels can be butted together but where it is required to form a door or window or have an infill panel or a louvre panel, the construction panels 3 are spaced apart with the gap between the panels of a size consistent with the building feature required. In Figure 8 a section through a building according to the present invention is illustrated showing a louvre panel that would be particularly suitable or required in buildings erected where the culture or climate requires free ventilation through the erected building. The louvre panel 30 is shown having a storm shutter 31 which is hinged to fold back into the position 31a when not protecting the louvre. A corner joint between construction panels according to the present invention is illustrated in Figures 10 and 11. In this case a connecting strap 32 at the top of the panel joins the angle members 18. The strap 32 is bolted to the sockets 10 on the adjacent panels as illustrated in Figure 10. The section between the panels as a compressible filler board 33 with a PEF backing rod 34 on either side thereof and the seal completed with a siϋcone sealant 35.
As will be apparent from the foregoing, an insulated construction panel according to the present invention can be constructed using a simple form work or
mould that has been built to the panel dimensions required. The method of constructing the panel is comparatively straightforward and can be adapted to utilise local resources where they meet the required building standards. Once the panels have been formed they are removed from the mould and cured and then erected on-site as described to produce a comparatively low cost typhoon proof building.