As per IS 456, the minimum percentage of reinforcement in concrete slabs when high yield strength deformed (HYSD) bars (such as Tor steel) are used is not less than:

For axial load and combined biaxial bending moment in the iteration formula used by IS 456, αn is based on Pu / Puz, where Puz is given by:

A compression member is considered to be short if its slenderness ratio satisfies which of the following conditions?