Structural formwork member

Abstract

A structural formwork member is disclosed. The structural formwork member includes a base member in the form of a profiled metal sheet that has parallel ribs ( 5 ) and plurality of pans ( 6 ) between the ribs. The structural member also includes a strengthening member ( 71 ) that is structurally connected to the base member.

1 . A structural formwork member comprising: 
 (a) a base member in the form of a profiled metal sheet, the base member including parallel ribs and plurality of pans between the ribs, the ribs being small ribs; and    (b) at least one strengthening member that is structurally connected to the base member.    
     
     
         2 . The structural formwork member defined in  claim 1  wherein the height of the ribs above the pans of the base member is no more than 20 mm.  
     
     
         3 . The structural formwork member defined in  claim 1  wherein the height of the ribs above the pans of the base member is no more than 15 mm.  
     
     
         4 . The structural formwork member defined in  claim 1  wherein the height of the ribs above the pans of the base member is no more than 10 mm.  
     
     
         5 . The structural formwork member defined in  claim 1  wherein the height of the ribs above the pans of the base member is no more than 20% of the height of the strengthening member above the pans.  
     
     
         6 . The structural formwork member defined in  claim 5  wherein the height of the ribs of the base member above the pans is no more than 15% of the height of the strengthening member above the pans.  
     
     
         7 . The structural formwork member defined in  claim 1  wherein the height and the number of the ribs of the base member is selected so that the width of the base member is at least 80% of the width of a flat sheet prior to forming the ribs in the flat sheet and producing the base member.  
     
     
         8 . The structural formwork member defined in  claim 1  wherein the strengthening member includes a lattice girder formed from a top chord element that is spaced above the base member and web chord elements that are connected to the top chord element and to the ribs and/or pans of the base member.  
     
     
         9 . The structural formwork member defined in  claim 8  wherein the lattice girder also includes bottom chord elements that are parallel to the top chord element and are connected to the web chord elements.  
     
     
         10 . The structural formwork member defined in  claim 1  wherein the strengthening member is in the form of an inverted channel member.  
     
     
         11 . The structural formwork member defined in  claim 10  wherein the inverted channel member has a top wall and two sides, with the sides being connected to the top wall member and the base being spaced above the base member.  
     
     
         12 . A structural formwork member comprising: 
 (a) a base member in the form of a metal sheet; and    (b) at least one strengthening member in the form of an inverted channel member that is structurally connected to the base member.    
     
     
         13 . The structural formwork member defined in  claim 12  wherein the base member is in the form of a flat metal sheet.  
     
     
         14 . The structural formwork member defined in  claim 12  wherein the base member is in the form of a profiled metal sheet and includes parallel ribs that extend along the length of the base member and a plurality of pans between the ribs.  
     
     
         15 . The structural formwork member defined in  claim 14  wherein the ribs are small ribs.  
     
     
         16 . The structural formwork member defined in  claim 12  wherein the channel member has a top wall and two sides, with the sides being connected to the base member and the base being spaced above the top wall member.  
     
     
         17 . The structural formwork member defined in claim  12  wherein the channel member is formed from a roll-formed metal sheet.  
     
     
         18 . The structural formwork member defined in  claim 17  wherein the roll-formed sheet is 0.6-1.2 mm thick.  
     
     
         19 . The structural formwork member defined in  claim 17  wherein the thickness of the roll-formed sheet is 0.6-0.8 mm.  
     
     
         20 . The structural formwork member defined in  claim 12  wherein the height of the channel member is 80-240 mm.  
     
     
         21 . The structural formwork member defined in  claim 12  wherein the height of the channel member is 130-240 mm.  
     
     
         22 . The structural formwork member defined in  claim 12  wherein the width of the channel member, measured between the connections of the sides of the channel member to the base member, is 90-190 mm.  
     
     
         23 . The structural formwork member defined in  claim 12  wherein the sides of the channel member have outwardly turned flanges to improve the connections between the sides of the channel member and the base member.  
     
     
         24 . The structural formwork member defined in  claim 12  wherein one or both sides of the channel member include sections that are pressed or otherwise formed out of the plane of the side or sides to provide resistance to local buckling of the structural formwork member and to increase the shear capacity of the structural formwork member.  
     
     
         25 . The structural formwork member defined in  claim 24  wherein the pressed sections are ribs or corrugations in the side or sides.  
     
     
         26 . The structural formwork member defined in  claim 25  wherein the axes of the ribs extend transversely to the lengthwise direction of the base member.  
     
     
         27 . The structural formwork member defined in  claim 25  wherein the crests and the troughs of the corrugations extend transversely to the lengthwise direction of the base member.  
     
     
         28 . The structural formwork member defined in  claim 12  wherein the channel member and the base member define a water impermeable void to minimise transverse deflection of the structural formwork member when wet concrete is poured onto the member in the construction of a composite slab and/or to provide an access pathway for building services, such as telecommunications cables, in the completed composite slab.  
     
     
         29 . The structural formwork member defined in  claim 12  wherein one or both sides of the channel member include openings to allow access to the interior of the channel member, whereby wet concrete can flow into the volume defined by the channel member and the base member during construction of a composite slab.  
     
     
         30 . The structural formwork member defined in  claim 12  wherein the sides of the channel member include aligned openings to allow reinforcing bars/wires/cables to be positioned to extend transversely through the channel member during construction of a composite slab.  
     
     
         31 . The structural formwork member defined in  claim 12  wherein the channel member further includes a top chord element mounted to or retained by the channel member.  
     
     
         32 . The structural formwork member defined in  claim 31  wherein the top chord element is a bar or a rod or a plate.  
     
     
         33 . The structural formwork member defined in  claim 32  wherein the plate has up-turned and/or down-turned sections to improve mechanical interlock of the structural formwork member with concrete in a composite slab.  
     
     
         34 . A structural formwork member comprising: 
 (a) a base member in the form of a metal sheet;    (b) at least one strengthening member that is structurally connected to the base member; and    (c) a bridging member that is connected to one or both ends of the member and/or at one or more locations along the length of the member to enable direct load transfer from the strengthening member to temporary or permanent supports for the structural formwork member.    
     
     
         35 . The structural formwork member defined in  claim 34  wherein the bridging member is in the form of a chord element connected to the strengthening member.  
     
     
         36 . The structural formwork member defined in  claim 35  wherein the chord element is in the form of a frame.  
     
     
         37 . The structural formwork member defined in  claim 35  wherein the chord element includes a means that permits adjustable connection of the chord element to the strengthening member.  
     
     
         38 . The structural formwork member defined in  claim 34  wherein the bridging member is in the form of a panel formed from steel sheet or plate.  
     
     
         39 . The structural formwork member defined in  claim 34  wherein the bridging member is in the form of an elongate member, such as a beam and a plate, connected to the base member of the structural formwork member.  
     
     
         40 . The structural formwork member defined in  claim 34  wherein the strengthening member includes a lattice girder formed from a top chord element that is spaced above the base member and web chord elements that are connected to the top chord element and to the base member.  
     
     
         41 . The structural formwork member defined in  claim 40  wherein the lattice girder also includes bottom chord elements that are parallel to the top chord element and are connected to the web chord elements.  
     
     
         42 . The structural formwork member defined in  claim 34  wherein the strengthening member is in the form of an inverted channel member.  
     
     
         43 . The structural formwork member defined in  claim 42  wherein the inverted channel member has a top wall and two sides, with the sides being connected to the top wall member and the base being spaced above the base member.  
     
     
         44 . A structural formwork member comprising: 
 (a) a base member in the form of a metal sheet;    (b) a plurality of strengthening members that are structurally connected to the base member; and    (c) a water impermeable void that contacts a section of the base member between adjacent strengthening members to minimise transverse deflection of the section when wet concrete is poured onto the structural formwork member.    
     
     
         45 . The structural formwork member defined in  claim 44  wherein the void does not function as a structural member.  
     
     
         46 . The structural formwork member defined in  claim 44  wherein the void extends across a substantial part of the width of the section of the base member that is between adjacent strengthening members.  
     
     
         47 . The structural formwork member defined in  claim 44  wherein the void extends across at least 70% of the section of the base member that is between adjacent strengthening members.  
     
     
         48 . The structural formwork member defined in  claim 44 , further comprising a plurality of voids spaced along the length of the section of the base member that is between adjacent strengthening members.  
     
     
         49 . The structural formwork member defined in  claim 44 , further comprising a single void extending along the length of the section of the base member that is between adjacent strengthening members.  
     
     
         50 . The structural formwork member defined in  claim 44  wherein the void is small in terms of height so as to make it possible to use the member in the construction of composite slabs that will be subject to significant 2-way bending action and therefore require a significant amount of reinforcement or pre-stressing in a direction transverse to the strengthening member to strengthen the composite slab.  
     
     
         51 . The structural formwork member defined in  claim 44  wherein the void is defined by a block of material that is adhered or otherwise secured to the base member.  
     
     
         52 . The structural formwork member defined in  claim 44  wherein the base member is in the form of a profiled metal sheet that has lengthwise extending ribs and pans between the ribs.  
     
     
         53 . The structural formwork member defined in  claim 52  wherein the void is defined by a volume enclosed by (i) the base member, (ii) the sides of ribs of the base member or other suitable members that are adjacent to a section of the base member that is between adjacent strengthening members, and (iii) a sheet of material spaced above the base member and extending across the section and contacting the adjacent ribs or other suitable members.  
     
     
         54 . The structural formwork member defined in any  claim 52  wherein the void is defined by a volume enclosed by (i) the base member and (ii) a shaped sheet of material that has sides that are retained by the ribs of the base member or other suitable retaining members.  
     
     
         55 . The structural formwork member defined in  claim 52  wherein the void is defined, by way of further example, by a volume enclosed by (i) the base member, and (ii) a channel member in an upturned position, with the base of the channel member spaced above the base member and forming the top of the void and the sides of the channel member extending downwardly and being structurally attached to the base member and forming two other sides of the void.  
     
     
         56 . (canceled)  
     
     
         57 . (canceled)  
     
     
         58 . A composite floor slab comprising: 
 (a) a structural formwork member which comprises: 
 (i) a base member in the form of a profiled metal sheet, the base member including parallel ribs and a plurality of pans between the ribs, the ribs being small ribs; and  
 (ii) at least one strengthening member that is structurally connected to the base member; and  
   (b) a layer of hardened concrete disposed on the structural formwork member.    
     
     
         59 . A composite slab in the form of a vertical wall panel, comprising: 
 (a) a structural formwork member which comprises: 
 (i) a base member in the form of a profiled metal sheet, the base member including parallel ribs and a plurality of pans between the ribs, the ribs being small ribs; and  
 (ii) at least one strengthening member that is structurally connected to the base member; and  
   (b) a layer of hardened concrete or other suitable castable panel material disposed on the structural formwork member.