Written by: Engr Sami Ullah Stanikzai ( www.civilglobal.com)
In this article I will teach you how to find out the steel quantity for a column. after reading this article you will be able to find out the quantity of different types of column and also you can find the materials for any object with the help of this article.
Given data for Column:
This is the top view of the column and i have deigned it in the auto-cad software and you can get the data from this image which is the front of you. but those formulas which I am using to find out the weight of steel in column. these formulas you can use at site to find out the weight of steel for column or beam. This is just the example, so you can bring it to real estimate. lets get start.
Length of Column = L = 400mm
Breadth of column = B = 300 mm
The Height of the Column is = Height = 3m
Nos of Steel Bars = Nos = 4
Clear Cover = 25 mm
Diameter of Steel which we used in this column = D = 12mm
Diameter of stirrups = D = 8 mm
Lets start solution for for Above Column
Now we have to Find out the Unite Weigh of steel for Longitudinal bar in column for 12mm diameter of steel.
Use this formula for Unite Weight of steel.
D2 / 162
Here D is the Diameter of Steel which is 12mm
12 x 12 / 162 = 0.88kg/m
Now Total Length of Longitudinal (Main Bars) , So Height of column is 3m its mean each bar height is also 3m
So we have 4 NOs of steel used in above Column see in the above image.
3 meter is steel height and 4 is Nos of steel
Total length of steel for column = 3 x 4 = 12m
Now Weight of Longitudinal bar = Unite Weight of steel x Total Length of steel = 0.88 x 12 = 10.66 kg
Now we have to find out the weight of stirrups for above column.
Spacing between Two Stirrups = C/C = 30 cm = 0.30m
Now we need Total numbers of stirrups
Use this formula = Total height of Column / Spacing of Stirrups = 3 / .30 +1 = 11 No’s
Now we Need Each Stirrup Cutting Length:
Length of 400mm side = ( 400-25 ) (2) Here 400 mm is length of stirrup from top view and 25mm is the concrete cover so we have to subtract the clear cover and 2 mean we have other opposite side see in above image.
So , Length of 300 side = (300-25) (2)
Now Cutting length of Stirrup = ( 400-25 ) (2) + (300-25) (2) + 10Dx2 – 2D x 5
Here 10D is used for the length of Hooks which is in the stirrup and 2D used for Subtract the bent and 5 is nos of bent. and “D” should be used the Dia of Steel for stirrup
Now total Length = 880 mm = 0.88 m
Total Length of Stirrups = One stirrup cutting length x No’s = 0.88 x 10 = 8.8 kg
Total weight of steel which use in the above Column = 10.66 + 8.8 = 19.46 Say 20 Kg.
Note : the above calculation is the detail calculation to find out how to calculate weight of steel in column with stirrups and in the stirrups the Hook’s should be design or place with the 135 degree this point is too much important . and may be it will be ask from you in the interview for Civil Engineering vacancy.
written by: Engr Sami Ullah (www.civilglobal.com)