Average values for typical concrete frames: Heavy industrial = 130 kg/m 3 Commercial = 100 kg/m 3 ... we can find the number of bars by the formula below [ Length / Spacing] + 1 = number of bars [ 6800 / 150] + 1 = 46.33 In this case, we always round up. Hence, we require 47 stirrups. Cutting Length: We must remember than steel is ductile in ...