| 摘要 |
Apparatus for forming hollow upright concrete structures by the jump-forming technique is disclosed which is particularly suited to structures where significant changes in circumference are required, as for example, in hyperbolic cooling towers. The apparatus comprises a plurality of units each consisting of a line of inner shutter panels (1A) and a line of outer shutter panels (1B), individual panels having common dimensions and being releasably incorporated in their line such that the overall length of the line can be changed (to suit changes in structure circumference) by adding or removing panels. Resultant changes in radius are simply accommodated by adjusting a tie assembly (6) interconnecting bracing carried by each panel. The lines of panels are carried by support post assemblies (9) relative to which they are pivotable and the lines of panels and their support post assemblies are securable to the structure being formed by brackets. During concrete formation the brackets are in lowered positions relative to the post assemblies (9). Lifting of the units for forming further concrete is effected by releasing the brackets but not the panels from the structure, raising the brackets and re-securing them to the structure at raised positions relative to the post assemblies, releasing the panels but not the brackets from the structure, raising the post assemblies and hence the panels relative to the brackets, and re-securing the panels to the structure with the brackets again at their lowered positions relative to the post assemblies. <IMAGE> |
