The quantity of steel varies in several structural elements since load (tensile force) occupied by various components are different.

Load (tensile force) on beam is more than load on slab to some extent. Therefore, steel quantity in beam is marginally greater than slab & other structural components.

Therefore,

Slab /lintel - 0.7 to 1.0% (55 to 78.5kg)/m^3

Columns - 0.8 to 6.0% (62.80 to 471kg)/m^3

Beam - 1.0 to 2.0% (78.5 to 157kg)/m^3

Foundation - 0.5 to 0.8% (39.25 to 62.80)/m^3

Note:-

Generally, it is not recommended to exceed 4 %( 314kg/m^3) reinforcement in Column as it will be complicated to pour concrete and compact it”.

To obtain the perfect quantity of steel the components should be designed on the basis of standard codes guidelines.

In this construction video tutorial presented by the renowned engineer, S.L.Khan, you will learn how to the measure the quantity of steel in a beam with length 10 feet and depth 18 inches. The dimension of hook in two main bars is taken as 9d. Two bent up bars are provided in beam with an angel of 45 degree with the horizontal lines.

There are two sections in the beam. One is located at mid span and other is located adjacent to the supports.

The above structural drawings are submitted by the designer. The quantity surveyors can determine the quantity of steels from these structural drawings.

Initially, it is required to determine the quantity of steel for straight main bars. There are total 5 bars like two bent up bars and four straight bars.

The total cut length of bars will be determined with the following formula:-

= [Total length of the beam – 2 times concrete cover for one side & another side + 2 times hooks]

= [10 feet – 2(c.c) + 2(hooks)] x Number of bars

= [10’ – 2(1”) + 2(9(6/8”)] x 4 (as #6 means 6/8 inches and hook lengh is 9d i.e. 9 times of the diameter of the bar)

= 43.83 feet

Now, it is required to calculate the steel for bent up bars. For this purpose, go through the following video tutorial.

Video Courtesy : Engineer Boy