Concrete is a composite material composed of ingredients like cement, water, aggregates (fine & course aggregates) and sometimes admixture or additives to enhance the properties of mixture which harden over the period of time to gain it’s characteristic strength, durability and workability. Before we know other aspects of the concrete, in this blog we will discuss how to calculate the quantity of cement, sand, gravels and water to make 1 cubic metre of concrete mix.
Concrete Mix Ratios:
Concrete is a versatile material used in construction to build road, bridges, dams and building. The quantity of different materials for concrete mix depends on the types and grades of concrete. The significance of concrete mix ratios is used in determining the proportion of cement, sand and coarse aggregate.
Components of Concrete :
The role of each component of the ingredients in concrete is crucial in determining its properties. Each ingredient’s proportion and quality are carefully controlled under the checking of engineers to achieve the desired performance and the requirements of the construction projects.
- Cement :- Cement acts as the binding agent that holds the fine aggregates and coarse aggregate together to hold. It reacts with water to foam a fluid paste that coat the other components and hardens to give concrete its strength, workability and durability to last long.
- Water :- Water initiates the chemical reaction with cement, known as hydration, which causes the whole mixture to becomes harden and set at the final time. The addition of water depends on the water cement ratios for the concrete as it affects the workability and strength of the concrete.
- Aggregates :- The fine and coarse aggregates such as sand, gravel, crushed stones provides the bulk to the concrete, reducing the amount cement needed to fill the voids.
- Admixture :- Additional materials like additives or admixtures are added to the concrete to modify its properties. Admixture can improve workability, reduce water contents, enhance durability and accelerate or delay setting time.
Material Quantity for 1 Cubic Metre of Concrete :
The quantity of materials required to produce 1 cubic metre of concrete depends on the desired mix design and specific characteristics of the material used. When we find out the total quantity of any component for concreting on site, it is considered a wet volume. So converting the wet volume to dry volume is essential for accurately determining material quantity. The volume of concrete changes when transitioning from wet to dry. Specifically, for every 1 cubiv metre of concrete, you’ll find 1.54 cubic metre of dry concrete due to the voids in sand and coarse aggregates. This discrepancy means the dry volume of concrete is 54% more than the wet volume of concrete.
Calculation of Components in M25 Concrete Mix Ratio :
Let’s calculate the quantity of components required to make M25 ratio concrete mix design. Here are some factors we are considering in determining the quantities of cement, sand, and coarse aggregate.
- Ratio of M25 concrete mix is 1:1:2
- Dry volume of 1 cubic metre of concrete = 1.54 m³
- Density of cement 1440 kg/m³.
- Density of sand ranges from 1600 to 1800 kg/m³.
- Density of coarse aggregate ranges from 1480 to 2100 kg/m³.
- Water cement ratios ranges from 0.35 to 0.50.
All the considerations varies based on factors like climate, workability, strength and quality of materials.
Quantity of Cement :-
Volume of cement = (M25 cement proportion / sum of M25 ratio) × Dry volume
= (1/4) × 1.54
= 0.385 m³.
Weight of cement = volume × Density (Density of cement = 1440 kg/m³)
= 0.385 × 1440
= 554.4 kg
But cement comes in bags and weight of one bag is 50 kg.
Thus no. of bags = 554.4 / 50 = 11 bags.
Therefore, at least 11 bags of cement will be needed for M25 concrete per m³.
Quantity of Sand :-
Volume of sand = (M25 sand proportion / sum of M25 ratio) × Dry volume
= (1/4) × 1.54
= 0.385 m³.
Weight of sand = volume × Density (Density of sand = 1740 kg/m³)
= 0.385 × 1740
= 669.9 kg
Similarly, approximately 0.67 metric tonne of sand will be required for 1 cubic metre of M25 concrete.
Quantity of Aggregates :-
Volume of aggregate = (M25 aggregate proportion / sum of M25 ratio) × Dry volume
= (2/4) × 1.54
= 0.77 m³.
Weight of aggregate = Volume × Density (Density of aggregate = 1550 kg/m³)
= 0.770 × 1550
= 1193.5 kg
Similarly, approximately 1.2 metric tonne of aggregate will be required for 1 cubic metre of M25 concrete.
Quantity of Water :-
As per IS code you can calculate water quantity with the help of water cement ratio, which is approximately 0.55.
weight of water = 0.55 × 554.4 = 304.92 kg.
So required water to produce a 1 cubic metre of M25 concrete mix is approximately 305 litre.
Conclusion :-
By following the calculation done, you can conclude that to produce 1 cubic metre of M25 concrete mix design as per IS CODE, approximately 11 bags of cement, 670kg of sand, 1200 kg of aggregate and 305 litre of water is required.
Also read,
2 thoughts on “How much cement, sand and coarse aggregate are required for 1 cubic meter of concrete work?”