What is Lap Length?
Lap Length is required when bars placed short of their required length (due to nonavailability of longer bars) need to be extended. Lap Length is also required when the bar diameter has to be changed along the length (as is sometimes done in columns). Branding The purpose of Lap is to transfer the axial force effectively from the terminating bar into the connecting bar with this same line of action in the junction. This invariably introduces stress concentrations at this surrounding concrete. These effects should be minimized by
Type of Lapping Method
1- Lapping of bars (lap splice)
2- Welding of bars (welded splice)
3- Mechanical connection
Where is the best zone of lapping in beams?
In Beams, there is compression Zone at the top and tension Zone at bottom of the section. The best zone of lapping is where tension is low. For Top reinforcement in the beam is lapped at mid-span, In case of bottom reinforcement, it is lapped near the ends, not in the distance of 2h from the column edge(h: beam’s effective height)
Top reinforcement in the beam is lapped at mid-span as the beam does not experience any negative moment at midspan and so lapping is great in that region. In case of bottom reinforcement, it is lapped near the ends and again the same concept applies as there will be no positive moment at the ends of the beam.