Example:
Column size = 250mm×250mm
Column height = 3.1 m
Steel bar used = 4 nos
Dia of bar = 12mm
Stirrup spacing = 150mm
Dia of stirrup = 8mm
Volume of column = length×breadth×height
= 0.25×0.25×3.1 m cube
= 0.19375 m cube
Concrete grade M20 mix ratio-1:1.5:3
1 m cube concrete
required - 8 bag cement
- 15 cft sand
- 30 cft aggregate
Cement = 0.19375×8
= 1.55 bag
Rate Rs-380 per bag = 1.55×380
= Rs-589
Sand = 0.19375×15 cft
= 2.9 cft
Rate Rs-45 per cft = 2.9×45
= Rs-131
Aggregate = 0.19375×30 cft
= 5.81 cft
Rate Rs-30 per cft = 5.81×30
= Rs-175
Steel bar
(i) Main bar = 4×3.1 m
= 12.4 m
Weight = (D×D× length)/162 kg
= (12×12×12.4)/162 kg
= 11.02 kg
(ii) stirrup bar
No. of stirrup = (height/spacing )+1
= (3.1/0.150)+1
= 21.66
Let = 22 nos
Total stirrup length = 22×0.648 m
= 14.25 m
Weight = (D×D×length)/162 kg
= (8×8×14.25)/162 kg
= 5.62 kg
Total steel weight = 11.02+5.62 kg
= 16.64 kg
Let = 17 kg
Rate Rs-50 per kg = 17×50
= Rs-850
Total column cost = 589+131+175+850
= Rs-1745 ans.
