Most of the reinforced concrete structures won’t be provided with full-length rebars. The manufacture and transportation of long bars are difficult, which limits the use of full length reinforced bars.

The method used to join the reinforcement bars, so that the force is transferred effectively from one rebar to the other rebar is called as rebar mechanical splicing. The integrity of the concrete structure is dependent on the proper mechanical splicing of the reinforcement bars.

The forces are transferred from one bar to the other through bonds in concrete. Force is first transferred to the concrete through a bond from one bar and then it is transferred to the other bar forming the splice through the bond between it and concrete. Thus, concrete at the point of splicing is subjected to high shear and splitting stresses which may cause cracks in concrete. A properly designed splicing is the key element in transmitting the forces through the reinforcement bars by creating a proper load path.

Methods of Reinforcement Bars Mechanical Splicing

#1 Lap Splice

#2 Mechanical Splice

#3 Welded Splice

The requirement of reinforcement bar splicing is covered in the specification. The Specification also specifies that the splicing of flexural members should not be at sections where the bending moment is more than 50% of the moment of resistance, and not more than 50% of reinforcement bars should be spliced at any given section. The splicing of bars should be carried out for alternate bars if more than one bar has to be spliced.