Difference between Development Length and Lapping Length

In this article toady I will teach you the difference b/w Lap length and development length so after reading this article you will be able about lap length and development length in detail.

Lapping Length

In civil Engineering point of view the lapping length is also called overlapping length, and lapping length we can define when the steel in bar is not sufficient for the design length which we required, so for that we lap the other steel to complete the design length , so there two steel should be overlapping on each other that is called lapping or overlapping length.

Lapping length can transfer the load from on e member to other, and the reinforcement bar need to be firmly bind at both ends.

Example: If we have to place the steel on the slab and the length of the slab is 22 meter, And in the market there we have the steel length which is 12 meter so if we complete our design length for steel in slab so we have to over lap the other steel to complete  our steel design for slab.

we have two kind of lapping in steel

Lap length for tension members = 40d   ( Specially used for Beam )

Lap length for compression members = 50d.   ( Specially used for Column )

The above formula you can use at site for practical construction work, Because this is the real design structure formula

Development Length

Development length is the length of bar which we used to transferring the stress into concrete.

We used the given formula

Development length (Ld) =d x σs/τbd

So here

d is Dimmeter of bar

σs = Stress in the bar at the section considered as design load.

τbd = Design bond stress.

Also Read: Reinforcement Lapping Zone Formulas For beam and Column

written by: Engr Sami Ullah Stanikzai



Engr Sami Ullah Author

Founder & Admin of civilengineeringinfo.com I am Civil Engineer working as a Site Engineer. With a good subject knowledge in civil Engineering. And I have started the blog to share my valuable information with civil engineer students. Civil Global is the Civil Engineering learning Home around all over the world.



    (March 2, 2018 - 10:59 pm)

    So beneficial. Best source of knowledge

    Shubham singh

    (March 3, 2018 - 3:39 am)

    I like the lapping detail which is shared..

    Rajesh surani

    (March 3, 2018 - 2:10 pm)

    Lep and L, footing

    […] Also read: Difference between Development Length and Lapping Length […]

    Kebek Chaka

    (March 16, 2018 - 8:14 am)

    I like it really!

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