Column formwork improvements

Abstract

The present disclosure relates to formwork. In a particular form the present disclosure relates to lost column formwork. In one aspect, there is provided a lost column formwork shell portion comprising an elongate body comprising a generally u-shaped cross-section shape comprising a pair of lengthwise extending edges, an inner side and an outer side, and at least one spacer element depending from the inner side of the shell portion and projecting inwardly. In a further aspect, there is provided a lost column formwork shell assembly comprising a pair of shell portions joined along their lengthwise extending edges. In a further aspect, there is provided a lost column formwork assembly a shell assembly, bracing and reinforcement. The lost column formwork assembly ensures that the required axis distance is maintained across its length, is braced against bulging under the hydrostatic pressure of concrete filling, and is quicker and easier to assemble than commonly known alternatives.

1 . A lost column formwork assembly comprising:
 a. a first shell portion and a second shell portion, each shell portion comprises an elongate body comprising a pair of lengthwise extending edges, and an inner side and an outer side, wherein at least a first shell portion comprises a generally u-shaped cross-section, and the shell portions are adapted to cooperatively form a column shell by being joined along their lengthwise extending edges;   b. each shell portion further comprising at least one spacer element depending from an inner side of each shell portion and projecting inwardly;   c. and wherein at least the second shell portion comprises an aperture extending therethrough between the inner side and the outer side thereof, via which the spacer element for this portion can be secured thereto;   d. the lost formwork assembly further comprising:   e. at least one brace element of sufficient length to bridge opposing inner sides of the two shell portions; and   f. a column reinforcement framework; and   g. wherein the two shell portions are joined along their lengthwise extending edges to form a column shell, with the column reinforcement framework extending lengthwise through the shell and separated from the shell by the spacing elements, and with the or each bracing element extending through the reinforcement framework and between opposing inner sides of the two shell portions, and secured at opposing ends thereof with respect to the inner sides of the two shell portions.   
     
     
         2 . The lost column formwork assembly of  claim 1 , wherein each shell portion comprises an elongate body comprising a generally u-shaped cross-section shape comprising a pair of lengthwise extending edges, and an inner side and an outer side, and adapted to cooperatively form a column shell by being joined along their lengthwise extending edges. 
     
     
         3 . The lost column formwork assembly of  claim 1 , further comprising a plurality of the brace elements arranged in parallel, extending transversely across the shell and spaced apart lengthwise therealong. 
     
     
         4 . The lost column formwork assembly of  claim 1 , wherein each spacer element comprises a generally u-shaped cross-sectional shape arranged with an opening to its u-shape directed inwardly and opposing another spacer element, and wherein each end of each bracing element is positioned in the opening of one of a pair of opposing spacer elements, and secured at each end to its respective spacer element, and thus with respect to the respective shell portion in turn. 
     
     
         5 . A method for assembling a lost column formwork assembly comprising:
 a. a first shell portion and a second shell portion, each shell portion comprises an elongate body comprising a pair of lengthwise extending edges, and an inner side and an outer side, wherein at least a first shell portion comprises a generally u-shaped cross-section, and the shell portions are adapted to cooperatively form a column shell by being joined along their lengthwise extending edges;   b. each shell portion further comprising at least one spacer element depending from an inner side of each shell portion and projecting inwardly;   c. where the or each spacer element for the second shell portion is separate to this prior to assembly;   d. and wherein at least the second shell portion comprises an aperture extending therethrough between the inner side and the outer side thereof, via which the or each spacer element for this portion can be secured thereto after the shell portions are joined;   e. the lost formwork assembly further comprising:   f. at least one brace element of sufficient length to bridge opposing inner sides of the two shell portions; and   g. a column reinforcement framework; and   h. the method of assembly comprising the steps of:   i. nesting the reinforcement framework in the first of the shell portions so that this is separated from the shell by the spacing elements, inserting the or each bracing element through the reinforcement framework and securing them, securing the second shell portion to the first shell portion along the edges thereof; and then securing the or each spacer element for the second shell portion thereto via the or each of the apertures.   
     
     
         6 . The method of  claim 5 , wherein each spacer element comprises a generally u-shaped cross-sectional shape, and each spacer element is arranged with an opening to its u-shape directed inwardly, the method then comprising the further steps of locating each end of each bracing element in the opening of one of a pair of opposing spacer elements, securing each end to its respective spacer element, securing the second shell portion to the first shell portion along the edges thereof, and then securing the or each spacer element for the second shell portion thereto via the or each of the apertures. 
     
     
         7 . A lost column formwork shell assembly comprising:
 a first shell portion and a second shell portion, each shell portion comprising an elongate body comprising a pair of lengthwise extending edges, and an inner side and an outer side, wherein at least a first shell portion comprises a generally u-shaped cross-section, and the shell portions are adapted to cooperatively form a column shell by being joined along their lengthwise extending edges;   each shell portion further comprising at least one spacer element depending from an inner side of each shell portion and projecting inwardly; and   wherein at least the second shell portion comprises at least one aperture extending therethrough between the inner side and the outer side thereof, via which the spacer element for this portion can be secured thereto.   
     
     
         8 . The lost column formwork shell assembly of  claim 7 , wherein at least the second shell portion comprises a line of the through apertures spaced apart there along, via which the spacer element for this portion can be secured thereto. 
     
     
         9 . The lost column formwork shell assembly of  claim 7 , wherein at least the second shell portion comprises at least a pair of parallel lines of the through apertures spaced apart there along, via which a pair of parallel spacer elements for this portion can be secured thereto. 
     
     
         10 . The lost column formwork shell assembly of  claim 7 , wherein first shell and second shell portion cooperatively form a column shell of rectilinear cross-section shape. 
     
     
         11 . The lost column formwork shell assembly of  claim 7 , wherein first shell and second shell portion cooperatively form a column shell of rounded cross-section shape. 
     
     
         12 . A lost column formwork shell portion comprising an elongate body comprising a generally u-shaped cross-section shape comprising a pair of lengthwise extending edges, an inner side and an outer side, and at least one spacer element depending from the inner side of the shell portion and projecting inwardly. 
     
     
         13 . The lost column formwork shell portion of  claim 12 , wherein this comprises three straight sides, a first side, and then a pair of parallel sides extending from the first side. 
     
     
         14 . The lost column formwork shell portion of  claim 12 , wherein at least one spacer element depends from each of the three sides of the lost column formwork shell portion. 
     
     
         15 . The lost column formwork shell portion of  claim 12 , wherein each spacer element comprises a generally u-shaped cross-sectional shape. 
     
     
         16 . The lost column formwork shell portion of  claim 12 , wherein each spacer element is arranged with an opening to its u-shape directed inwardly. 
     
     
         17 . The lost column formwork shell portion of  claim 12 , wherein each spacer element is elongate and extends along the column formwork shell portion. 
     
     
         18 . The lost column formwork shell portion of  claim 17 , wherein a side comprises two or more spacer elements, these are spaced apart and extend parallel to each other. 
     
     
         19 . The lost column formwork shell portion of  claim 12 , wherein in one form, each spacer comprises a length of parallel flange channel (PFC). 
     
     
         20 . The lost column formwork shell portion of  claim 12 , wherein the cross-section shape of the lost column formwork shell portion comprises a semi-circle.