How to determine the quantity of steel in a slab in KG

In this exclusive civil engineering video tutorial, you will learn how to find the quantity of steel in slab.

The dimension of the slab is given as follow :- Length = 18 feet, Breadth = 14 feet

Here, the steel bars applied in long distances are known as main bars and the steel bars applied in short distances are known as distribution bars.

Main bars are taken as #4 @6" c/c and distribution bars as #4 @6" c/c.

Concrete cover is not considered here.

The calculation of main bars is done as follow :-
Numbers of main bars = total distance / c/c + 1

After putting the values, we get the following result :-
Numbers of main bars = 18 / 0.5 + 1 = 37 (6" = 0.5 feet)
Now, total length of main bars = length of one bar x Numbers of bars
Total length of main bars = 14 x 37 = 518 feet

As the bars are available in market in kg or tons, so, it is necessary to convert the total length into kg with the following formula :-

Weight of bar = D² / 52.9 x L (D stands for diameter)

Also Read: How to measure steel in a circular RCC Slab

Weight of bar = 4² / 52.9 x 518
Weight of bar = 0.3025 x 518 = 156.695 kg

The calculation of distribution bars is done as follow :-
Numbers of distribution bars = total distance / c/c + 1
Numbers of distribution bars = 14/0.5 + 1 = 29 (6" = 0.5 feet)
Total length of distribution bars = length of one bar x Numbers of bars
Total length of distribution bars = 18 x 29 = 522 feet

To convert the value in kg, apply the following formula :-
Weight of bar = D²/52.9 x L = 4² / 52.9 x 522
Weight of bar = 0.3025 x 522 = 157.905 kg
So, weight of main bars = 156.695 kg
Weight of distribution bars = 157.905 kg
Total weight = 323.6 kg
To convert it to ton, 323.6 / 1000

To get more details, go through the following video tutorial.

Video Source: Site Engineer