The steel reinforcement mostly is divided into two categories i.e.

#1 Primary reinforcement or main steel reinforcement

#2 Secondary reinforcement or distribution reinforcement

Main steel reinforcement bars are employed in R.C.C structures to ensure resistance against the whole design loads coming over it. The secondary reinforcement bars are mainly employed due to durability as well as for aesthetic reasons.

This reinforcement guarantee resistance for localized areas, like limited cracking. These also offer resistance to the stresses that are created due to temperature variations.

The main bars employed of specified diameter are bent at the ends. The stirrups are reinforcements that are provided laterally, to keep the main bars of the structural elements like beams and columns, in position.

The stirrups may be circular, square, rectangular, helical or diamond shape based on the cross-section of the structural element. The reinforcement bars in the corners may be L – shaped.

The caging for the structural element under consideration must be properly tied, so that during concreting no bar is disturbed from its position. This is a check to be always kept in mind during concreting, else it is a threat to the durability of the structural member.

The rebars are mainly provided at the junctions where the formwork of the structural element is closed as well as at the point where a new structural element needs to be bond with the former one.