Introduction
Concrete is a widely used construction material that consists of cement, sand, aggregate, and water. The proportions of these materials determine the strength and durability of the concrete mix.
In this blog post, we will discuss how to calculate the quantity of cement, sand, aggregate, and water for 1m³ of M20 grade concrete. The Procedure for calculating Quantity for any other Grade of concrete is also like this.
M20 grade concrete is a commonly used mix design that has a compressive strength of 20 N/mm² at 28 days. The mix proportion for M20 grade concrete is 1:1.5:3 (cement:sand:aggregate). Let us calculate the quantities of materials for concrete.
Quantity of Cement
Cement is the most vital component of concrete that provides strength and binds the other components together.
To calculate the quantity of cement required for 1m³ of M20 grade concrete, we need to know the proportion of cement in the mix design, the total volume of the mix, and the density of cement.
Given, the proportion of cement in the mix design = 1 part
The total volume of the wet mix = 1 m³
The total volume of the Dry mix = 1.54 m³ (Volume of Dry mix = 1.54 times Volume of wet Mix)
Density of cement = 1440 kg/m³
To calculate the quantity of cement required, we can use the following formula:
Quantity of cement = (Proportion of cement / Total proportion) x Volume of Dry mix concrete
Quantity of cement = (1 / 5.5) x 1.54 = 0.28 m³
Weight of cement per m³ = Density of cement = 1440 kg
Therefore, the weight of cement required for 1m³ of M20 grade concrete = 0.28 x 1440 = 403.2 kg
As one bag of cement weighs 50 kg, the number of bags required = 403.2 / 50 = 8.064 ≈ 8 bags (rounding off to the nearest whole number)
Quantity of Sand
Sand is a fine aggregate that fills the voids between the coarse aggregate and provides work-ability to the concrete mix.
To calculate the quantity of sand required for 1m³ of M20 grade concrete, we need to know the proportion of sand in the mix design, the total volume of the mix, and the density of sand.
Given, the proportion of sand in the mix design = 1.5 parts for M20 grade concrete
Density of sand = 1600 kg/m³
The total volume of the Dry mix = 1.54 m³ (Volume of Dry mix = 1.54 times Volume of wet Mix)
To calculate the quantity of sand required, we can use the following formula:
Quantity of sand = (Proportion of sand / Total proportion) x Volume of concrete
Quantity of sand = (1.5 / 5.5) x 1.54 = 0.42 m³
Quantity of sand (in Cubic Feet) = 0.42 * 35.315 = 14.83 ≈ 15 CFT
If Quantity of sand is required in Kg, use the following step.
Density of sand = 1600 Kg/m3
Weight of sand required for 1m3 of M20 grade concrete = 0.42 * 1600 = 672 Kg
Quantity of Coarse Aggregate
Aggregate is a coarse material that provides strength and durability to the concrete mix.
To calculate the quantity of aggregate required for 1m³ of M20 grade concrete, we need to know the proportion of aggregate in the mix design, the total volume of the mix, and the density of aggregate.
Given, the proportion of aggregate in the mix design = 3 parts for M20 grade concrete
The total volume of the Dry mix = 1.54 m³ (Volume of Dry mix = 1.54 times Volume of wet Mix)
Density of aggregate = 1520 kg/m³
To calculate the quantity of aggregate required, we can use the following formula:
Quantity of aggregate = (Proportion of aggregate / Total proportion) x Volume of concrete
Quantity of aggregate = (3 / 5.5) x 1.54 = 0.84 m³
Quantity of aggregate (in Cubic Feet) = 0.84 * 35.315 = 29.66 ≈ 30 CFT
If Quantity of aggregate is required in Kg, use the following step.
Density of aggregate = 1520 Kg/m3
Weight of aggregate required for 1m3 of M20 grade concrete = 0.84 * 1520 = 1277 Kg
Quantity of Water
Water is an essential component of concrete that is required for the hydration of cement and provides work-ability to the mix.
To calculate the quantity of water required for 1m³ of M20 grade concrete, we need to know the water-cement ratio and the weight of cement.
The water-cement ratio = 0.5
Weight of cement required = 403.2 kg
To calculate the quantity of water required, we can use the following formula:
Quantity of water = Water-cement ratio x Weight of cement
Quantity of water = 0.5 x 403.2 = 201.6 ≈ 200 Kg
As 1 liter of water weighs 1 kg, the quantity of water required = 200 liters
Conclusion
The table below summarizes the quantity of each component required for 1m³ of M20 grade concrete:
| Component | Quantity | Unit |
| Cement | 8 | Bags |
| Sand | 15 | CFT |
| Coarse Aggregate | 30 | CFT |
| Water | 200 | Liters |
Calculating the quantity of cement, sand, aggregate and water is essential for designing a concrete mix that meets the desired strength and durability requirements.
By using the mix proportion and density of each component, we can easily calculate the quantity of each component required for any volume of concrete.