As per IS 456:2000, what is the minimum percentage of vertical reinforcement required for a reinforced concrete wall when using high strength deformed bars like Fe415?

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?