Lapped splices in tensile reinforcement are generally not used for bars of size larger than

Question

Question

This question was previously asked in

BPSC AE Paper 5 (Civil) 14 Oct 2022 Official Paper

Answer 1

Explanation:

Lap splice:

It is done by overlapping the bars over a certain length, thereby making possible the transfer of axial force from the terminating bar to the connecting bar by the mechanism of anchoring (development) bond with the surrounding concrete.
According to 3rd amendment of IS 456: 2000 in 2007, the value was changed from 36 mm to 32 mm.
So, 36 mm is an old provision and 32 mm is a new provision
32 is not given in the given options, so we have to go with the old provision ie 36 mm

Additional Information

However, where welding is not practicable, CI. 26.2.5.1(a) of IS 456:2000 recommends the use of additional spirals around the lapped bars.
It is always desirable to bend the bars slightly (especially for large diameter bars) at the location of the splice in order to have a collinear force transfer without any eccentricity.
As per IS 456, the straight length of the lap should not be less than 15ϕ or 200 mm (whichever is more).
The lap length must be at least equal to the development length.
In no case, the lap length should be less than 30ϕ for flexural and direct tension and 24ϕ for compression.
When two different diameter bars meet at the splice location then lap length should be calculated based on the smaller bar diameter.
Splices in tension members should be enclosed by spirals made up of bars of diameter not less than 6 mm along with pitch not exceeding 100 mm