What is the cement concrete?
Cement concrete is a mixture of cement, sand, and aggregate. Generally cement concrete mix is prepared in two ways one is ‘nominal mix’ and the other is ‘design mix’.
Soved has created concrete nominal mix material calculator based on nominal mix ratio allowing us to easily calculate concrete content with different grades.
In nominal mix, the proportion of concrete and grade of concrete are written below-
| Grade of concrete | Nominal mix ratio |
| M5 | 1:5:10 |
| M7.5 | 1:4:8 |
| M10 | 1:3:6 |
| M15 | 1:2:4 |
| M20 | 1:1.5:3 |
| M25 | 1:1:2 |
In the Grade of concrete symbol first letter M stands for mix and second number stands for after curing 28days of cement concrete then strength should be greater than or equal to written value in N/mm2. And ratio is ‘cement : sand : aggregate’.
Where cement grade is OPC-33 or PPC equivalent to 33grade. For coarse sand and aggregate strength, it should be higher than 33N/mm2 or concrete grade with multiply of safety factor whichever is greater.
Example: Calculate the quantity of cement, sand and aggregates of 1Cum and 5.5Cum M10 grade concrete.
Solution:
As we know that M10 grade concrete ratio is 1:3:6,
Concrete wet volume= 1cum
So dry volume of concrete= 1*1.54= 1.54cum
Dry volume is 50% to 58% more than wet volume due to filling of voids by smaller sized material.
Cement quantity= Dry volume of concrete*Cement ratio no./(sum of all ratio no.)
Cement quantity= 1.54*1/(1+3+6)
Cement quantity= 1.54/10
Cement quantity= 0.154Cum
Sand quantity= Dry volume of concrete*Sand ratio no./(sum of all ratio no.)
Sand quantity= 1.54*3/(1+3+6)
Sand quantity= 4.62/10
Sand quantity= 0.462Cum
Aggregate quantity= Dry volume of concrete*Aggregate ratio no./(sum of all ratio no.)
Aggregate quantity= 1.54*6/(1+3+6)
Aggregate quantity= 9.24/10
Aggregate quantity= 0.924Cum
Now for 10mm, 20mm and 40mm Aggregate quantity we use 1:2:4 ratio. Generally we do not use 40mm size aggregate in RCC work, but at some places 40mm aggregate is used in PCC and heavy RCC work. When graded method is used for aggregates we do not need to calculate it separately. But we know that graded aggregate is not available in the market so we are using the ratio method.
Here we are using only 10/12.5mm and 20/25mm aggregate for cement concrete work in the ratio of 1:2
So 10/12.5mm aggregate= 0.924*1/3
10/12.5mm aggregate= 0.308Cum
20/25mm aggregate= 0.924*2/3
20/25mm aggregate= 0.616Cum
List of 1Cum cement concrete material quantity-
Cement- 0.154Cum
Sand- 0.462Cum
10mm aggregate- 0.308Cum
20mm aggregate- 0.616Cum
For 5.5Cum cement concrete multiply by 5.5 in 1Cum concrete quantities.
For Quantity in kg multiply by material density-
Cement density- 1440kg/cum
Sand bulk density (loose fill or without rodded)- 1600- 1800kg/cum
10mm aggregate bulk density (loose fill or without rodded)- 1400- 1500kg/cum
20mm aggregate bulk density (loose fill or without rodded)- 1350-1450kg/cum
The density of sand and aggregate varies from site to site, so it is best to check the density of sand and aggregate for your site yourself.
For cubic feet quantity multiply by 35.314 in Cum quantity.
For water cement ratio, Maximum w/c ratio given by IS code 456
According to above image for M10 grade concrete max water cement ratio= 34/50= 0.68
Max water for 1cum quantity= 0.68*0.154*1440= 150.8kg= 150.8Ltr