Corrugated formwork for concrete stairs - has dihedral corrugations with horizontal and inclined sections supported by stringers

摘要

The shuttering for reinforced concrete stairs uses dihedral corrugated panels in which alternate corrugations are flat (9) and inclined (10). There are two dihedral sections to each stair tread and by overlapping the horizontal sections of the panels, the shuttering can be made to follow the path of a spiral staircase. For a rotating staircase, the axis of rotation of the panels is determined by a helical stringer. For straight section of stair, the stringer is straight. Using corrugated shuttering, the volume of concrete used is less than with flat panels and the inconvenience of using stair shaped shuttering with complicated reinforcement is avoided.