As per IS 456:2000, cl 26.5.2.2 the maximum diameter of the reinforcement bar that can be used in a slab shall not exceed one-eight of the total thickness of the slab.
Problem based on maximum dia of the bar in the slab as per IS 456
Problem 1 – We have a slab of 125 mm and find the max no of dia of bars we can use in the slab.
Solution
As the code suggests the max dia of the bar does not exceed 1/8 of the thickness of the slab
1×125/8 = 15.62 = 16 mm dia bar
which means we can not use more than 16mm dia bars in a 125mm thickness slab.
Problem 2 – We have a slab of 5 inches and find out the max no of dia of bars we can use in the slab.
Solution
First, convert slab thickness which is in inches to mm
5 inches x 25.4 = 127 mm
127/8 = 15.87 i.e. 16mm dia bar
We can use max 16mm dia bar for 5 inches slab