- To resist Hogging (Negative Bending Moment) at supports.
- To counter the risk of the failure of the slabs.
- To encounter the shear force. The shear force is always greater in the sections of supports.
- By providing crank the strength of slab increased.
The crank bars or bent up bar are very important in R.C.C beam or slabs construction because without countering the Hogging (Negative moment) the structure will fail or the strength of the structure will reduce. The hogging bending moment will develop at the supports of the slabs and beams.