False formwork for moulding concrete panels

Abstract

A false formwork system ( 40 ) includes a plurality of sideforms ( 17 ) which are able to be interconnected to define a perimeter of an opening in a panel to be cast. A support structure ( 24 ) is carried by the sideforms ( 17 ) for supporting components ( 26 ) used to mould a false skim coat overlying the opening when the panel is cast. An opening demarcation portion ( 21 ) is carried by each of at least some of the sideforms ( 17 ). Each opening demarcation portion ( 21 ) defines a zone of weakness to demarcate the skim coat of the cast panel from a remainder of the panel and to facilitate removal of the skim coat from the remainder of the panel by breakage along the zone of weakness.

1 . A false formwork system which includes
 a plurality of sideforms which are able to be interconnected to define a perimeter of an opening in a panel to be cast;   a support structure carried by the sideforms for supporting components used to mould a false skim coat overlying the opening when the panel is cast; and   an opening demarcation portion carried by each of at least some of the sideforms, each opening demarcation portion defining a zone of weakness to demarcate the skim coat of the cast panel from a remainder of the panel and to facilitate removal of the skim coat from the remainder of the panel by breakage along the zone of weakness.   
   
   
       2 . The system of  claim 1  in which each sideform is connected to an adjoining sideform by a corner form. 
   
   
       3 . The system of  claim 2  in which each sideform has a receiving formation in which a mating formation of the corner form is receivable. 
   
   
       4 . The system of  claim 1  in which each sideform is an angle section having a foot portion and an element extending substantially orthogonally from the element, the element defining the opening demarcation portion. 
   
   
       5 . The system of  claim 4  in which the opening demarcation portion of each sideform is a bevel surface defining portion projecting at an angle from the element in a direction away from the foot portion of the element to form a bevel on one perimetral edge of the opening in the panel. 
   
   
       6 . The system of  claim 5  in which the support structure of each sideform is a ledge arranged on the element intermediate the opening demarcation portion and the foot portion, the ledge extending substantially parallel to, and in the same direction as, the foot portion. 
   
   
       7 . The system of  claim 5  in which each sideform includes an attachment formation for attaching a bevel surface defining member of an elastomeric material for imparting a bevel to an opposed perimetral edge of the opening in the panel. 
   
   
       8 . The system of  claim 7  which includes the bevel surface defining member for each sideform, each member being removably attachable to its associated sideform to enable the member to be removed from its sideform to facilitate removal of the sideform from the opening in the panel. 
   
   
       9 . The system of  claim 1  which includes an intermediate support member for supporting the components to form the false skim coat, the intermediate support member being of a dimension to support the components at a position less than a thickness of the panel to be cast. 
   
   
       10 . A method of casting a concrete panel, the method including erecting a
 plurality of sideforms on a base to define an outer periphery of a panel to be cast;   erecting false formwork within the sideforms to define an opening in the panel to be cast;
 demarcating at least a portion of a periphery of the opening; 
 mounting infill in the false formwork so that the infill lies at a level lower than a surface of the panel to be cast; 
 pouring concrete into the sideforms so that the concrete overlies the infill to define a false skim coat over the opening; and 
 allowing the concrete to set to provide an uninterrupted upper surface of the panel. 
   
   
   
       11 . The method of  claim 10  which includes demarcating the at least portion of the periphery of the opening by forming a line of weakness in the cast concrete from below the upper surface of the panel. 
   
   
       12 . The method of  claim 10  which includes casting a further panel on the panel previously cast in substantially the same manner as the panel previously cast and using the previously cast panel as the base for the further panel to be cast. 
   
   
       13 . The method of  claim 10  which includes, once the concrete has been finished and allowed to set, removing the sideforms, raising the panel and removing the infill. 
   
   
       14 . The method of  claim 13  which includes breaking away the false skim coat along the demarcated periphery of the opening. 
   
   
       15 . The method of  claim 14  which includes removing the false formwork for re-use.