As an Engineer on site, you must know the amount of cement and sand require for a particular volume of concrete.
Knowing this will prevent you from running loss. I will explain to you how to calculate the amount of cement and sand require for any volume of concrete.
The calculations below is all about 1:2:4 mix ratio of Concrete
CALCULATING FOR CEMENT
TOTAL RATIO = 1+2+4
Cement = 1
Sand = 2
Granite = 4
We are dealing with cement, we have 1/7 = 0.143
For 1m³ of cement = 1m³ * 0.143
Addition of waste and shrinkage 54% = (54/100 * 0.143) + 0.143
= 0.0772m³ + 0.143m³
Density = Mass/Volume
1440 = 50/Volume
Volume = 0.03472m³
1 Bag of Cement = 0.03472m³
Y Bags of Cement = 1m³
Y = 1/0.03472
Y = 28.8 bags of Cement
1m³ of cement = 28.8 bags
0.22m³ of cement = X bags
X = 6.3 bags of cement
Now for 1:2:4 mix ratio, the number of cement require to mix 1m³ of concrete
= 6.3 bags.
Assuming you are to calculate the amount of cement require for 0.55m³ of concrete
1m³ of Concrete = 6.3 bags of cement
0.55m³ of concrete = X bags of cement
X = 3.47 bags of cement.
This means 3.47 bags of cement will mix 0.55m³ of concrete using 1 : 2 : 4 mix Ratio
CALCULATING FOR SAND
TOTAL RATIO = 1+2+4 = 7
Since we are dealing with sand, we have 2/7 = 0.285
For 1m³ of sand = 1m³ * 0.285
Addition of 35% bulking = 0.099m³
Addition of 10% waste = 0.03m³
= 0.285 + 0.099 + 0.03
0.65m³ of sand = 1 ton of sand
0.414m³ of sand = x tons of sand
X = 0.637 tons.
Now for 1:2:4 mix ratio, the number of sand require to mix 1m³ of concrete
= 0.637 tons.
Assuming you are to calculate the amount of sand require for 0.55m³ of concrete
1m³ of concrete = 0.637 tons of sand
0.55m³ of concrete = X tons of sand
X = 0.35 tons of Sand
This means 0.35 tons of sand will mix 0.55m³ of concrete using 1 : 2 : 4 mix Ratio
This is a must know calculation for Engineer, Quantity Surveyor and Site Manager on site to avoid wastage of Materials
Comment below to ask question, Add or Subtract
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