TUTORIALS
Estimation of the amount of cement, sand and aggregate in plain concrete
In this tutorial, we are going to show you how to calculate the amount of cement, sand and aggregate in 1 m3. We have M15 concrete mix.
M15 concrete mix is equal to 1:2:4, where 1 is for cement, 2 for sand and 4 is for aggregate.
Cement density is equal to 1440 kg/m3
1 m3 is equal to 35.3147 ft3
Wet Volume or Concrete volume is equal to 1 m x `1 m x 1 m is equal to 1 m3
Concrete Dry Volume is equal to 1 x 1.54 is equal to 1.54 m3
[Why multiplied with 1.54]
Concrete Dry Volume (Aggregate + Sand + Cement) is equal to fifty four percent more than wet volume.
Is equal to 100 divided by 100 + 54 divided by 100
Is equal to 1 + 0.54
Is equal to 1.54
Therefore, 1.54 x wet volume
Let’s compute the cement quantity:
1) In m3 = part of cement/ratio addition x 1.54 = 1/7 x 1.54 is equal to 0.22 m3
2) In kg = 1/7 x 1.54 x cement density = 1/7 x 1.54 x 1440 = 316.8 kg
3) In bags = value of kg/one cement bag = 316.8/50 = 6.336 bags
4) In ft3 = technique A: 0.22 x 35.3147 = 7.76 ft3
Technique B: number of bags x volume of one cement bag = 6.336 x 1.226 = 7.76 ft3
[VERIFICATION for volume of one cement bag]
Cement density = 1440 kg/m3
One cement bag mass = 50 kg
One cement bag volume = mass/density = 50/1440 = 0.0347 m3
Changed in ft3 = 0.0347 x 35.3147 = 1.226 ft3
Hence verified
Now let’s compute sand quantity
Things to remember
Unit weight of wet sand = 1760 to 2000 kg/m3
Unit weight of dry sand = 1540 to 1600 kg/m3
Concrete dry volume = 1.54 m3
1 m3 is equal to 35.3147 ft3
M15 is equal to 1:2:4
1) In m3 = 2/7 x 1.54 = 0.44 m3
2) In kg = 2/7 x 1.54 x unit weight of dry sand = 2/7 x 1.54 x 1540 = 677.6 kg
3) In ft3, technique A: 0.44 x 35.3147 = 15.54 ft3
Technique B: 6.336 x 1.226 x sand ratio = 6.336 x 1.226 x 2 = 15.54 ft3
Now let’s compute aggregate quantity
1) In m3 = 4/7 x 1.54 = 0.88 m3
2) In kg = 4/7 x 1.54 x 1500 = 1320 kg [unit weight of aggregate = 1440 to 1600 kg/m3]
3) In ft3, technique A: 0.88 x 35.3147 = 31.07 ft3
Technique B: 6.336 x 1.226 x 4 (aggregate ratio) = 31.07 ft3
Therefore, for M15 mix (1:2:4)
Cement quantity = 7.76 ft3
Sand quantity = 15.54 ft3
Aggregate quantity = 31.07 ft3
ANOTHER WAY
Volume = 1 m3
M15 concrete mix is equal to 1:2:4 = 1 + 2 + 4
Constants:
Cement density is equal to 1440 kg/m3
1 m3 is equal to 35.3147 ft3
A) [ Wet volume ] Concrete volume is equal to 1 x 1 x 1 = 1 m3
B) Concrete Dry Volume is equal to 1 x 1.54 = 1.54 m3
C) Cement quantity in bags is equal to 1/7 x 1.54 x 1440/50 kg = 6.336 bags
D) In ft3 : 6.336 x 1.226 = 7.76 ft3
E) Sand quantity is equal to 7.76 x 2 = 15.54 ft3
F) Aggregate quantity is equal to 7.76 x 4 = 31.07 ft3
Lecturer: TECH@7K
