📌📌 Different shape of bent up bars and cranks are provided in the slab and other structural members.
📌📌 Bars are bent near the supports normally at an angle of 45°. The angle bent may also be 30° in shallow beams where the (effective depth < 1.5 breadth).
▶️▶️ When bent up bars are provided, the strength and deformation capacity of slabs with bent up bars compared to slabs without bent up bars is sufficiently increased.
So crank bars are generally provided
☑️☑️ To resist negative bending moment (hogging).
☑️☑️ To resist shear force which is greater at supports.
☑️☑️ To reduce the risk of a brittle failure of slab-column connection.
☑️☑️ To reduce the amount of steel used.