The percentage of reinforcement in case of slabs, when high strength deformed bars are used is not less than

The Indian Standard IS 456:2000 specifies minimum reinforcement in slabs. When high-strength deformed (HYSD) bars are used, the minimum steel in either direction shall not be less than 0.12% of the gross cross-sectional area (bD).

For comparison, when plain/mild steel is used the minimum is 0.15% — the reduction to 0.12% is permitted because HYSD bars have higher yield strength and provide equivalent ductility with slightly less area of steel.

This requirement (clause on minimum reinforcement for slabs) ensures adequate cracking control and ductile behaviour of slabs while taking advantage of HYSD bar properties.