Classifications

• • E—FIXED CONSTRUCTIONS
  • E04—BUILDING
  • E04C—STRUCTURAL ELEMENTS; BUILDING MATERIALS
  • E04C2/00—Building elements of relatively thin form for the construction of parts of buildings, e.g. sheet materials, slabs, or panels
  • E04C2/02—Building elements of relatively thin form for the construction of parts of buildings, e.g. sheet materials, slabs, or panels characterised by specified materials
  • E04C2/04—Building elements of relatively thin form for the construction of parts of buildings, e.g. sheet materials, slabs, or panels characterised by specified materials of concrete or other stone-like material; of asbestos cement; of cement and other mineral fibres
  • E04C2/049—Building elements of relatively thin form for the construction of parts of buildings, e.g. sheet materials, slabs, or panels characterised by specified materials of concrete or other stone-like material; of asbestos cement; of cement and other mineral fibres completely or partially of insulating material, e.g. cellular concrete or foamed plaster
• • E—FIXED CONSTRUCTIONS
  • E04—BUILDING
  • E04C—STRUCTURAL ELEMENTS; BUILDING MATERIALS
  • E04C2/00—Building elements of relatively thin form for the construction of parts of buildings, e.g. sheet materials, slabs, or panels
  • E04C2/02—Building elements of relatively thin form for the construction of parts of buildings, e.g. sheet materials, slabs, or panels characterised by specified materials
  • E04C2/04—Building elements of relatively thin form for the construction of parts of buildings, e.g. sheet materials, slabs, or panels characterised by specified materials of concrete or other stone-like material; of asbestos cement; of cement and other mineral fibres
  • E04C2/06—Building elements of relatively thin form for the construction of parts of buildings, e.g. sheet materials, slabs, or panels characterised by specified materials of concrete or other stone-like material; of asbestos cement; of cement and other mineral fibres reinforced

Definitions

• This invention relates to an improved building panel. More particularly, this invention relates to a reinforced building panel, of the type having a slab of lightweight concrete or the like, optionally sandwiched between a pair of facing sheets and to a method of production thereof.
• this invention provides, in one aspect thereof, a building panel comprising a slab of lightweight concrete or the like having a pair of opposed faces characterised in that a number of flat structural metal strips is secured by means of suitable adhesive to each opposed face of said pair.
• the slab is of 600 kg/cubic metre lightweight concrete
• this will require a surface more than 200 mm wide to transfer the shear loads. That is, the flat metal (e.g., steel) is first bonded to the external sheet which is in turn bonded to the slab material.
• the slab material is, for example, 1400 kg/cubic metre, a 60 mm wide flat steel surface, bonded to the concrete, would be able to carry the shear loads.
• Dealing with a dense concrete of 2000 kg/cubic metre, a 8 mm rod could give enough grip to the ⁇ oncrete to carry the shear moment of the loading.
• a flat steel member can be placed in the most structurally advantageous position to give the maximum lever arm and can be successfully waterproofed.
• the round rod because of its shape, creates weaknesses in the concrete near the edges and would be in a structurally less advantageous position.
• the slab of lightweight concrete or the like is preferably foamed concrete and/or concrete containing a lightweight aggregate, such as expanded polystyrene foam beads, expanded vermiculite, expanded shale, any of the many accepted lightweight aggregates or mixtures thereof.
• a material such as plaster, as well as lightweight plaster, may be used.
• the preferred slab thickness relates to the overall panel thickness, as described later.
• a facing sheet is bonded to each said opposed face of the slab, over the metal strips.
• the facing sheets may be constructed of any suitable material.
• the facing sheets consist of fibre reinforced cement, fibre reinforced plaster, plaster faced with paper, or plywood. Any other accepted sheet lining is within the scope of this invention.
• the panel of the invention may be based on the STYROCON panel having fibre reinforced cement facing sheets, with added reinforcement provided by the metal strips.
• the panel of the invention may also be based on a 5 similar lightweight panel for internal use only, described in Australian Patent No. 473,993 of 1973.
• This panel has been manufactured in several countries under the Registered Trade Mark STYROPLAST and comprises a lightweight plaster core with paper-lined plaster sheets on the outside.
• Such a 10 metal-strip reinforced STYROPLAST panel may be useful in some situations; however, in most applications the metal-strip reinforced STYROCON panel will be preferred.
• the facing sheets vary in thickness between 3 mm and 6 mm. In special cases, the 15 thickness may be 9 mm.
• the overall thickness of the panels in the past has been between 30 mm and 100 mm.
• the structural metal strips used in the building panel of the invention are preferably steel strips. These may be galvanised if desired or coated, but galvanisation or
• metal should have a co-efficient of expansion similar to that of the concrete slab.
• a preferred range of thickness is 1.0 to 2.5 mm, with the strips being at least 25 mm wide; 50 mm is a preferred width.
• Factors to be taken into account when determining the thickness and width of the metal include the shear strength of the slab.
• the length of the strips will normally be chosen to approximate that of the panels. However, it may be convenient to have the strips a little shorter than the panels, to facilitate on-site adjustments to panel length.
• the metal strips may be corrugated or grooved transversely to the length of the strips, to provide for better adhesion between the strips and the slab and to hold the strips against movement in the longitudinal direction.
• the adhesive for securing the metal strips needs to be suited to the application described, bearing in mind the following requirements.
• the adhesive must be sufficiently waterproof under the conditions in which the building panel will be utilised, so that the adhesive will continue in its role of securing the metal strips to the inner faces of the sheets.
• the metal is susceptible to rust or other deterioration through contact with moisture (e.g., where the metal is steel), and where the metal is not otherwise waterproofed - for example, by galvanising -
• the adhesive should serve as a waterproof coating for the metal and the inner face of the sheet.
• the adhesive should not soften under the types of ambient temperature to be encountered by the panel of the invention. For example, where the panel is to be used for building construction in hot or tropical areas, the adhesive should be able to withstand ambient temperatures of 110 degrees Celsius or so.
• the adhesive should be applied to all surfaces of the metal strips. It should be noted that in the panel which includes facing sheets there is no necessity to provide adhesive between the metal strips and the slab material, although application of the adhesive to all or substantially all the surface area of the strips will give additional strength and safeguard against rusting, particularly if latex cement adhesive is used.
• cementitious adhesive especially a latex cement adhesive, since this will not adversely affect the fire-rating of the building panels of the invention and will give permanent compliance with all the above requirements.
• a polymer cement adhesive may also be suitable, for example.
• the metal strips are secured to opposite sides of the slab. It is preferred that the metal strips are of substantially uniform thickness, weight and strength and that they are disposed in a parallel manner on each side of the slab, with each strip being balanced by a strip placed substantially opposite. This gives an even degree of strength to the panel and fulfils the requirement of "balanced skins".
• the panel of the invention using metal strips of different thicknesses, for example, and to dispose the strips in a different manner, such as by staggering the strips on each side of the slab. It is not necessary that there be an identical number of strips on each side of the slab, although they have to be balanced by weight and positioning. The number of strips will depend on the desired strength of the panel.
• this invention provides a method of producing a building panel comprising: coating a number of flat structural metal strips with a suitable adhesive,
• the invention provides a method of producing a building panel comprising:
• the sheets with the attached metal strips are placed in the ' mould in a vertical position.
• the building panel so formed may be stripped from the mould after, say, 16 to 24 hours.
• the panel should be maintained in a vertical position during the whole curing process, which continues after removal of the panel from the mould.
• the panel should be wetted down for 4 to 5 days to aid even curing.
• Fig. 1 is a perspective view of a panel constructed in accordance with the invention
• Fig. 2 is a section of the panel prepared for testing, showing detail
• Fig. 3 is a diagrammatic view showing the loading of the test section of panel
• Fig. 4 is a diagrammatic view showing the deflection of the test section of panel
• Fig. 5 is a sectional view of part of a test panel constructed with round reinforcing rods.
• Fig. 6 is a sectional view of part of a test panel constructed with flat steel reinforcement, in accordance with the invention.
• the panel indicated generally at 10 comprises a slab 11 of lightweight concrete composed of a mixture of concrete and expanded polystyrene beads faced with sheets 12 formed of fibre reinforced cement, such as those marketed in Australia under the Registered trade mark “Hardiflex” or in Malaysia under the trade mark “Supaflex”.
• strips 14 of steel are secured to the inner face 16 of the sheets 12 by means of a suitable adhesive which is a latex-based cement.
• the strips are in the order of 1.0 to 1.6 mm in thickness and approximately 50 mm wide.
• the strips 14 extend the full length of the sheets 12 and are equally spaced across the width of the panel 10. The number of strips 14 and their dimensions may be varied, depending on the degree of strength required in the panel 10.
• the slab 11 has a thickness of approximately 41 mm.
• the panel 10 would resemble that in Fig 1, except that the sheets 12 would not be included.
• Figs 5 and 6 laminated panels are illustrated having a slab or core of lightweight concrete 11 and facing sheets 12.
• round reinforcing rods 18 are shown towards the outside of the slab 11, while in Fig. 6 flat steel strips 14 are adhered to facing sheets 12.
• the lever arm Assuming an overall panel thickness of 50 mm, with 4.5 mm skins and a 41 mm slab, using 10 mm diameter rods close to the external lining, the lever arm is 31 mm. Using 1.6 mm flat steel, the lever arm is 39.4 mm.
• the slab materials because of weight limitations, are very weak.
• the reinforcing steel is fixed to the external face of the slab over its whole surface area , which in the samples illustrated is 50 mm in width. Assuming that the 50 mm reinforcement is placed at 300 mm centres, this means that when a bending moment is applied to the panel, the shear force between the reinforcing steel and any lining sheet is transferred between the sheet and the slab material on a 250 mm width. In addition, if there is adhesion between the steel and the slab material a further 50 mm width is create to transfer the stresses from the slab to the steel.
• the shear moments decide the minimum strength which the slab has to have to enable it to use its tensile and compressive members when bending moments are applied, not dissimilarly to a truss where the top and bottom chords can be used to capacity only so long as the web members can withstand the force applied.
• the building panel of this invention provides a measure of strength combined with light weight in a form hitherto unknown. It will also be appreciated that the scope of the invention is not limited to the embodiments described above but only by the attached claims.

Landscapes

• Engineering & Computer Science (AREA)
• Architecture (AREA)
• Civil Engineering (AREA)
• Structural Engineering (AREA)
• Laminated Bodies (AREA)
• Finishing Walls (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (1)

Family

ID=3774551

Family Applications (1)

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Cited By (5)

Families Citing this family (2)

Citations (4)

• 1991
  • 1991-03-14 WO PCT/AU1991/000092 patent/WO1991014058A1/en unknown
  • 1991-03-15 IN IN225CA1991 patent/IN177643B/en unknown
  • 1991-03-22 TW TW80102262A patent/TW201807B/zh active
• 1992
  • 1992-09-09 GB GB9219134A patent/GB2258477B/en not_active Expired - Fee Related

Patent Citations (4)

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