Calculation method for finding out overlapping length of beam, column & slab
In this civil engineering article, you will get detail information on over lapping length of steel in slab, beam and column.
Given below, some important notes for civil engineers :-
As stated by IS Code 456-2000, overlapping should not remain under 75 mm.
Overlapping means the extra length arranged in the reinforcement steel bars. Here, two lengths are overlapped and attached with a wire to increase the length of any steel bar whenever necessary.
For column, the diameter of the steel should be 45D
For beam, the diameter of the steel should be 24D (for compression zone)
the diameter of the steel should be 50D (for tensile zone)
For slab, the diameter of the steel should be 60D
D stands for the diameter of steel bar.
While developing any structure, there are two major types of forces like tension and compression. Each material possesses the strength to retain a specific amount of tension and a compression. A tension force pulls the materials aside. A compression force compresses the material together.
Overlapping length of slab should be 60D = 60 x 12 = 720 mm (diameter of bar =12 mm)
Overlapping length of beam should be as follow :-
For compression zone = 24D = 24 x 12 = 288 mm
For tensile zone = 50D = 50 x 12 = 600 mm
In beam, there are two steel bars. One is located at top and one is located at bottom.
When the load is delivered to the top portion, it is compressed and when the load is delivered in lower portion, it gets tensiled.
Overlapping length of column should be 45D = 45 x 12 = 540 mm
To get more details, go through the following video tutorial.
Video Source: Civil Engineering