Patent ID: 8485493

Claim:
A concrete column-forming tube kit comprising: a plurality of wall sections, wherein each wall section extends along a longitudinal axis, and includes: i. an interior surface, ii. a top edge, iii. a bottom edge, iv. opposite side edges; and v. multiple interconnecting flanges extending radially outward from each of the opposite side edges, the multiple interconnecting flanges being spaced apart with respect to each other in the direction of the longitudinal axis, along each of the opposite side edges, wherein some of the multiple interconnecting flanges are adapted for sliding in the direction of the longitudinal axis to effect sliding interlocking engagement with respective others of the multiple interconnecting flanges of an adjacent one of the plurality of wall sections, at least some of the multiple interconnecting flanges comprising a hooked interconnecting element adapted for sliding in the direction of the longitudinal axis to effect sliding interlocking engagement with a complementary hooked interconnecting element of an adjacent one of the plurality of wall sections, wherein each of the hooked interconnecting elements of an interconnecting flange defines an interior region (i) extending in the direction of the longitudinal axis, (ii) having a uniform cross-section transverse to the longitudinal axis extending along the full axial length of the interconnecting flange, and (iii) adapted to receive a longitudinally extending portion of a hooked interconnecting element of one of the complementary interconnecting flanges of an adjacent one of the plurality of wall sections, wherein the plurality of wall sections are joinable together along adjacent side edges in interlocking engagement to form a closed side wall extending vertically between two opposing ends of a column-forming tube, the closed side wall defining a central lumen.