LAP LENGTH , DIFFERENCE BETWEEN LAP SPLICE LENGTH & DEVELOPMENT LENGTH

A Vision To Clear Solutions.

Lap Length Definition:

For column

When fc’=4000psi, Minimum lap length is 12 inch.

Or fy less or equal 60000psi, lap length=0.0005*fy*db where

db. is diameter of reinforcement in inch or mm

When fy is greater than 60000psi, lap= (0.0009fy-24)db.

When fc’ is less or equal 3000psi, required lap will multiply with 1.33333

For Beam

In tension Zone, Lap=60db, where db. in mm

In compression zone, lap=44db, where db. in mm

For Slab Lap=50db

The difference between lap splice length and development length is for rebar’s:

The difference between the two is in the application. A development length is the amount of rebar length that is needed to be embedded or projected into concrete to create a desired bond strength between the two materials. The lap splice length is the length two rebar pieces must overlap and be tied together to create a bond as if there was no break and the run is "continuous". So simply put, development is rebar to concrete, splice is rebar to rebar. The lengths of both splice and development do vary. They are dependent upon different factors. These include but are not limited to concrete strength, rebar size, rebar coating and concrete cover or clearance. So when you see a chart on one project, it can differ from another for these reasons.

Development Length:

Development length is the length overlap of bars tied to extend the reinforcement length. is about 50 times the dia of bar is consider to safe.

Anchorage Length:
Anchorage length- this is the additional length of bar required it insert in another at the junction.

 For example-Main bar of the beam in column at beam column junction. this length is similar to the lap length.