The quantity of steel calculation in the column is very easy and simple just needs you little concentration. For your better understanding just look at this example.
suppose we have a column. The height of the column is 4 m and has a cross-sectional area is 300 x 400 mm and a 40 mm clear cover. Six bars are going to use having a diameter of 16 mm. The diameter of the stirrup is 8 mm and has a spacing of 150 mm and @200 mm at L/3 respectively.
Height = 4 meter
Cross section = 300 x 400 mm
Clear cover = 40 mm.
No of vertical bars = 6 no’s.
The diameter of the vertical bar = is 16 mm.
Diameter of stirrup = 8 mm.
stirrups center to center spacing = @150 or @ 200 mm.
BBS of Column =?
The calculation was to proceed in two steps.
vertical bars calculation
Cutting length of stirrups
Step 1:Vertical Bar calculation
Length of 1 bar = H + Ld
Ld = development length
h = Height of column
Length of 1 bar
= 4000 mm + 40d <where d is dia of bar>
= 4000 + 40 x 16
= 4000 + 640
= 4640 mm or 4.640 m Ans..
The length of one vertical bar is 4.640 m. we have a total bar six bars,