Whenever the above requirements cannot be met, then the anchorage is achieved
with a large diameter drum
The minimum bend diameter Øm,min depends on the steel strength fyd, the strength of the con-crete fcd, the diameter Ø of the reinforcement bar and the axial distance ab between the adjacent bars according to the following formula:
• For bar or group of bars near the surface of the structural element ab=cover+Ø/2
• Strength fcd always lower than fcd of concrete class C55/67