Lap length and development length are extensions of the reinforcement bar. These two concepts are used while designing a structure. They are further implemented while making a bar bending schedule.
In this article, we will understand the difference between lap length and development length.
Lap Length:
When reinforcement bars come from the factory they are 12 meters long. This is the standard length of the reinforced bars.
In the construction work, we have to increase the length of the bar as per requirement.
When we increase the length of the bar, we have to overlap the reinforced bar to transfer the load safely. This overlapping length is known as lap length.
Lap length varies for various loading conditions.
Lap Length for Compression members = 40D
Lap Length for Tension members = 50D
Where,
D = Diameter of the bar
Development Length:
Development length is provided to establish the bond between concrete and reinforcement bars. Development length of reinforcement bar transfer load to the concrete.
Required rebar length to safely transfer load is known as development Length. It is represented by Ld. Development length is also called Anchorage Length.