WO1996007798A1

WO1996007798A1 - Structural panel

Info

Publication number: WO1996007798A1
Application number: PCT/AU1995/000591
Authority: WO
Inventors: Graham Shandiman; Kaine Telford
Original assignee: Graham Shandiman; Kaine Telford
Priority date: 1994-09-07
Filing date: 1995-09-07
Publication date: 1996-03-14
Also published as: AUPM793394A0

Abstract

There is provided a wall panel (10) including a frame structure (11) comprising intermediate frame members (12) provided with apertures through their webs, and outer side members (13) formed with complementary interlocking configurations to enable the panels to self align and interlock with one another. The frame structure (11) is designed to provide the necessary strength requirements of the wall panel. A rigid in-fill composition (15) is added as a pour-in composite material including cement, sand, perlite and synthetic rubber premixed and treated for air entrainment to reduce the density. Electrical and other services may be located in place prior to filling with infill material, and a moulded face of the structural panel wall (10) may incorporate a moulded-in pattern.

Description

STRUCTURALPANEL

This invention relates to structural panels and methods of forming same.

This invention has particular relevance to structural wall panels and methods of forming same and particular reference will be made to such systems. However this invention may be utilised for other structural panels such as floor and roof panels.

Many panelling systems have been proposed in the past to provide mass production of near finished wall panels.

However to date such systems have not been widely adopted. There are many reasons for this including the difficulty in complying with strict Building Codes in Australia, a perceived lack of integral strength, complexity of fabrication necessitating central manufacture of standardised panels using expensive production techniques and of course the resultant buyer resistance for mass produced housing which is difficult to personalise to suit the individual's requirements. The present invention aims to alleviate one or more of the above disadvantages and to provide structural panels and methods of forming same which will be reliable and efficient in use.

With the foregoing in view, this invention in one aspect resides broadly in a structural panel including:- a frame structure extending to or adjacent the external and/or internal extremities of the structural panel; said frame structure having intermediate frame members extending between a pair of opposed outer frame members, and a monolithic infill filling the panel frame structure between its external and/or internal extremities.

Suitably the solid infill is formed in-situ as a pourable self levelling liquid composite material which cures to a solid material. In the preferred form the solid infill is a mineral based composite material, preferably utilising a cement base. However, if desired, the solid infill may be a suitable polymer composite or other synthetic or organic material.

Preferably the composite mineral based material includes lightweight fillers such as periite, styrene or extendosphers which may be utilised in conjunction with stable air entrapment techniques in the formation of the infill, suitably utilising a chloride free air entraining agent so as to inhibit corrosion of the metal framing. Preferably the infill is formed with a mass density of between 350kg per M³ to 1200kg per M³ depending on specific requirements or specification.

The density of the infill material may be varied to achieve desired sound deadening properties, to increase fire resistance and/or insulation properties, or to provide increased structural performance, such as the load bearing characteristics of the structural panel or its impact resistance. Additives such as mono fibres and polymers may also be utilised. For enhanced sound deadening properties it is preferred that the density be maintained in the range 500kg per M³ to 650kg per M³ and preferably additive in the form of periite and/or liapor be added in the range of 10% by weight. For enhanced fire resistance and/or insulation properties it is preferred that the density be in the range of 650kg per M³ to 900kg per M³ and preferably additive in the form of periite and/or liapor in the form of aggregates be added in the range of 10% by weight.

For a non-structural wall of a dwelling it is preferred that the density be in the range of 350kg per M³ to 650kg per M³. For a structural wall of a single storey building it is preferred that the density be in the range of 650kg per M³ to 1200kg per M³. For a highrise infill panel it is preferred that the density be in the range of 650kg per M³ to 900 per M³. Polymer additives may be utilised to vary the viscosity of the liquid phase of the infill material whereby its flowability may be varied to ensure the infill material in its liquid phase flows through passages formed in any 5 internal parts of the panel frame structure whereby the infill is integral throughout the. structural panel.

For effective filling of the frame structure and working of the pourable self levelling liquid composite material which cures to form the monolithic infill, it is preferred

10 that the specific gravity be between 2.85 and 0.98.

The addition of additive may also be utilised to vary the curing time of the infill material and/or to achieve early high strengths of the material as maxim strength through curing of such materials may take place over many

15 years similar to concrete.

Polymer additives such as synthetic rubber (styrene butadine rubber or latex) may also be utilised to increase the adhesive qualities of the binder for a permanent bond to the panel frame structure and to provide external faces

20 suitable for the application or bonding thereto of protective or decorative coatings, plaster or panelling. In a preferred form the polymer in the composite is ultra violet stable and provides an increased Modulus of Rupture, providing increased flexibility of the panel frame structure. Suitably the

25 polymer has a specific gravity in the order of 1.1.

It is also preferred that polymer additive be used to enhance coalescence of a composite containing foam spheres of polymer, (surfactant of a soap solution) and to form a continuous polymer matrix which coats the hydrating grains of

30 cement and selected minerals and other fillers. Preferably the polymer is selected so as to act as a barrier which helps maintain high levels of internal moisture within the composite for improving hydration.

Inert fibres may be added to the composite in the range

35 500kg per M³ to 1000kg per M³ to increases its flexibility, enhance strength development and eliminate or ameliorate fragmentation and micro-cracking of the composite.

Suitably the panel frame structure is a metal frame having lightweight frame members with internal dividing members being formed with passages therethrough to enable the composite to be formed integrally within the panel frame structure. It is also preferred that the monolithic infill creates a stiff panel which resists lozenging and thus reduces cross-bracing requirements and the like. Suitably the frame members are rolled formed steel members but extruded metal or plastics frame members or combinations of or coated frame member materials may be used as desired.

It is also preferred that the panel frame structure be formed with a perimeter frame and suitably with outer frame components which enable adjacent panels to be interlocked through the configuration of their outer frame members. Preferably the interlocking means is of the type wherein raised wall panels can be slid horizontally into their operative interlocked positions. However if desired the interlocking means may be of the type that requires a panel to be interlocked with a standing panel to be elevated for engagement of the complementary interlocking components and lowered to its operative interlocked position.

In a preferred form of the invention the outer frame members and the intermediate frame members are open section steel members have opposed flanges terminating adjacent the opposed faces of the monolithic infill. The webs of the intermediate frame members extend continuously between their respective opposed flanges and are formed with spaced passageways spaced along the length of the webs through which a pourable self levelling liquid composite material may be distributed to cure to the monolithic infill.

The flanges at a common side or both sides of the structural panel may be exposed to provide visable metal sections which may be readily penetrated by self drilling/tapping screws to facilitate fastening a finishing sheet or material thereto or the flanges at each side of the structural panel may be encapsulated by the monolithic infill providing a continuous seamless panel surface. The outer frame members may be provided with stand-off formations enabling such panel frames to be laid horizontally on a moulding surface with substantially all the frame elevated above the moulding surface for receiving liquid or flowable infill material, contained by an outer former associated with the moulding surface, which will encapsulate the internal frame members. The stand-off formations may be fold-out tabs provided at spaced locations along the perimeter frames and formed by U-shaped cuts in the members. In another aspect this invention resides broadly in a method of forming the structural panel as variously defined above and including:- forming a panel frame structure; placing the panel frame structure on a substantially horizontal moulding surface, and filling the panel frame structure with a pourable self levelling liquid composite material which cures to form said monolithic infill.

The panel frame structure may be formed with internal openings such as windows or doorways and suitably the panel frame structure is so formed that it may be placed on a moulding surface, which is preferably a flat horizontal surface, to exclude penetration of poured-in material into such openings. That is the frame members defining the openings extend continuously to the moulding surface so as to form, a barrier to flow of in-fill material or at least to substantial quantities of the in-fill material into the internal opening to be formed.

Alternatively the panel frame structure may be adapted for mating with a moulding jig or jigs having raised retaining walls which co-operate with the frame structure and being adapted to permit selective filling of the panel frame structure. The jig or base moulding surface enables filling the panel frame structure with self levelling pour-in material and may incorporate a surface pattern. The polymer additive affording self-levelling of the liquid phase may be omitted to enable either lightweight or heavy in-fill material to be sprayed into place with the panel frame structure supported against a moulding surface which may be horizontal, inclined or vertical and which may incorporate a surface pattern.

In another aspect, this invention resides broadly in a method of forming the structural panel of the present invention, including:- providing a moulding jig assembly having raised retaining walls which permit filling of the frame structure; providing said retaining walls with jigging means co- operable with the frame structure; operating the jigging means to hold the frame member in an operative position within the retaining walls while filling the frame structure with a pourable self levelling liquid composite material which cures to form the monolithic infill; releasing the jigging means, and removing the structural panel from the moulding jig assembly after the monolithic infill has set.

In order that this invention may be more readily understood and put into practical effect, reference will now be made to the accompanying description of a composition, and drawings, which illustrate a typical embodiment of the invention and wherein:-

Fig. 1 illustrates a panel frame structure supported on a moulding surface ready to receive the in-fill material;

Fig. 2 illustrates the erection of a structure using structural panels of the present invention, the structural panels being shown with only part or without infill material in place;

Fig. 3 illustrates the edge joining of adjacent panels;

Fig. 4 illustrates wall roof connection; Fig. 5 illustrates a preferred floor mounting system, and

Figs. 6 to 8 illustrate some alternate moulding arrangements.

As illustrated a preferred form of wall panel 10 made in accordance with this invention includes a frame structure 11 made from galvanised rolled steel sections. The intermediate frame members 12 are provided with apertures through their webs, as illustrated at 12, and the outer side members 13 are formed with complementary interlocking configurations which are exposed in the completed structural panel 10 to enable the panels to self align and interlock with one another. Suitably the frame structure 11 is designed to provide the necessary strength requirements of the wall panel. The frame structure 11 may be a tab and slot type construction such as that manufactured by BHP under the trade mark SUPRAFRAME.

A rigid in-fill product 15 is integrally accommodated within the perimeter frame members 16. In this embodiment the infill is added as a pour in composite material based on cement and mineral filler material, and typically a composite of cement, sand, periite and synthetic rubber premixed and treated for air entrainment to reduce the mass to the required extent. The lightweight liquid infill is suitably added with the frame assembly laid horizontally on a moulding table 17. As the infill is a non-foaming material it is poured to the level of the uppermost edges of the outer frame members 16 where it will self level and cover the intermediate frame members 12 at one or both sides, depending on the configuration of the table and/or frame assembly 11. Electrical and other services may be located in place prior to filling with infill material. Retaining jacks 18 are utilised to hold the frame structure 11 in position on the table 17. Known non-corrosive polymer additives are added to the liquid composite to increase the rate of cure.

The moulded side of the structural panel wall 10 may incorporate a moulded-in pattern and the other side may be a screeded or natural finish and be adapted, by addition of suitable additives, to provide a surface to which cladding 19 or other surface finishes, such roofing sheets 20, may be adhered. Erection of such panels 10 to form a building structure is as per standard procedures for framed panel structures, a typical detail being illustrated in Fig. 3. However it is preferred that the peripheral side frames include complementary engagement features, such as tongue and groove features, to facilitate accurate erection and location of the panels.

It is also preferred that such panels be provided with access openings along the apertured base wall frame 21 to enable access to be gained to pre-located hold down bolts which upon erection of the wall panels, pass through the apertures therein. These apertures may be sealed for moulding of the in fill by a suitable flat strip held against the base wall frame 21 by the jacks 18. Preferably the hold down bolts are located by jigging means, as illustrated in Fig. 5 to ensure alignment with the base frame apertures. The access apertures may be concealed by a skirting board or filled after erection.

The pourable/sprayable variable density composite in-fill material can be chased or shaped with conventional tools after curing for additional plumbing or electrical services and simply repaired with sand/cement or plaster products etc.

The further moulding forms illustrated in Figs 6 to 8 may be used as selected to suit the application. In Fig. 6 it will be seen that the in-fill fully covers the sides of the frame, leaving the end faces thereof clear for frame to frame interlocking engagement. This embodiment utilises a full jig to contain the frame with appropriate spacers for holding the frame at the required position to achieve in-fill coverage of both opposing faces of the frame. The embodiment illustrated in Fig. 7 utilises the frame itself as the side containment for the composite and a supporting table as the base of the mould.

As illustrated in Fig. 8, the composite may be sprayed into a vertically disposed frame supported against a curtain which may become part of the finished composite panel. For this purpose the curtain is formed from a geofabric encapsulated with a cement based coating. The coating may be applied on a patterned mould surface to provide an external finish and it is preferably polymer modified for flexibility whereby the curtain may be rolled for storage and the like. Suitably the curtain has a thickness of between 1mm to 6mm. The curtain may also be applied to standing walls utilising a bonding agent to adhere the curtain to the cured surface of the infill material. By way of exemplification of the infill compositions of the present invention, a suitable infill composition of density of approximately 600 kg¹"^-3 is provided as follows, in parts by weight:

Component Parts Portland cement 612

Sand 612

Air entrainer 2.2 stryrene/butadiene rubber emulsion (57% solids) 45.9 methyl hydroxyethylcellulose 2.041 fume silica 64 polypropylene fibre (12mm staple) 2.4

(cont. over) periite 122 water 300

* Horn & Hoof Meal

It will of course be understood that the above has been given by way of illustrative example of the present invention and that all such modifications and variations thereto as would be apparent to persons skilled in the art are deemed to fall within the broad scope and ambit of the invention as is defined in the appended claims.

Claims

THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:-

1. A structural panel including:- a frame structure extending to or adjacent the external and/or internal extremities of the structural panel; 5 said frame structure having intermediate frame members extending between a pair of opposed outer frame members, and a monolithic infill filling the panel frame structure between its external and/or internal extremities.

2. A structural panel as claimed in claim 1, wherein said 10 outer frame members and said intermediate frame members are open section steel members having opposed flanges terminating adjacent the opposed faces of the monolithic infill, and wherein the webs of the intermediate frame members extending continuously between their respective 15 opposed flanges are formed with spaced passageways spaced along the length of the webs.

3. A structural panel as claimed in claim 2, wherein the flanges at a common side of said structural panel are exposed.

204. A structural panel as claimed in claim 2, wherein the flanges at each side of said structural panel are encapsulated by said monolithic infill.

5. A structural panel as claimed in any one of the preceding claims, wherein said monolithic infill is cement and mineral based composite material.

6. A structural panel as claimed in claim 5, wherein said composite material includes lightweight fillers including mineral such as periite and liapor.

7. A structural panel as claimed in any one of the preceding claims, wherein said frame members are rolled formed steel members.

8. A method of forming the structural panel defined in any one of claims 1 to 7, including:- forming a panel frame structure; placing the panel frame structure on a substantially horizontal moulding surface, and filling the panel frame structure with a pourable self levelling liquid composite material which cures to form said monolithic infill.

9. A method as claimed in claim 8, wherein the pourable self-levelling liquid composite material cures to form said monolithic infill having a mass density of between 350kg per M³ to 1200kg per M³.

10. A method as claimed in claim 8 or claim 9, wherein the mass desired density is achieved by reducing the mass density with a lightweight filler.

11. A method as claimed in claim 10, wherein the lightweight filler includes extendosphers, liapor and\or periite.

12. A method as claimed in any one of claims 8 to 11, including utilising a chloride free air entraining agent to provide stable air entrapment in the monolithic infill.

13. A method as claimed in any one of claims 8 to 12, including:- forming the panel frame structure with internal frame members which define window or doorway openings, and providing the substantially horizontal moulding surface with portions which cooperate with said internal frame members to exclude penetration of pourable self levelling liquid composite material into the window or doorway openings.

14. A method as claimed in any one of claims 7 to 12, including:- providing a moulding jig assembly having raised retaining walls which permit filling of the frame structure; providing said retaining walls with jigging means co- operable with the frame structure; operating the jigging means to hold said frame member in an operative position within said retaining walls while 5 filling the frame structure with a pourable self levelling liquid composite material which cures to form said monolithic infill; releasing the jigging means, and removing the structural panel from the moulding jig 10 assembly after the monolithic infill has set.

14. A method as claimed in any one of claims 7 to 13, including forming the pourable self levelling liquid composite material with a binder additive to increase the adhesion between the monolithic infill and the frame

15 structure.

15. A method as claimed in any one of claims 7 to 14, including forming the perimeter frame for a wall panel having upright end frame members provided with complementary interlocking formations.

20 16. A method as claimed in claim 15, wherein the opposite upright end frame members of said wall panels include interlocking tongue and groove formations.

17. A method as claimed in any one of claims 7 to 16, including forming the perimeter frame for a wall panel with stand-off formations enabling such panel frames to be laid horizontally on a moulding surface with substantially all the frame members elevated above the moulding surface.

18. A structural panel formed by the method as claimed in any one of claims 8 to 17.