The concrete is widely used construction material in the construction projects and it should be of a good quality to get maximum strength utilised in construction. 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.
M20 Concrete Ratio: Mix, Material Calculation & Applications.
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 for M20 concrete grade mix.
Also read,
Concrete Admixture : Types, Benefits, and Applications.
What is CPM in Project Management in Civil Engineering?
Concrete Slump Test : Detailed Procedure and Best Practices.
How Freelance Civil Engineers Can Earn a Steady Income?
What is the M20 Concrete Ratio?
M20 concrete ratio of 1 : 1.5 : 3 means 1 part of cement is mixed with 1.5 parts of fine aggregates and 3 parts of coarse aggregate gains a compressive strength of 20 N/mm² or MPa after 28 days of curing period. Simply put, the M20 concrete ratio is the percentage that the concrete is mixed with to get the required 20 N/mm² or MPa compressive strength.
It shows the highest stress that the concrete can withstand before cracking or shearing. It is an ordinary concrete grade that is used in building projects that need average compressive strength. M20 concrete grade is used to build residential and low-rise buildings, as well as supports, floors, walkways, parking roads, etc. and other structural parts like tie beam.
Material Quantity for 1 Cubic Metre of M20 Grade 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 cubic 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 M20 Concrete Mix Ratio :
Let’s calculate the quantity of components required to make M20 ratio concrete mix design. Here are some factors we are considering in determining the quantities of cement, sand, and coarse aggregate.
- Ratio of M20 concrete mix is 1:1.5:3.
- 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.
Also read,
What is Self Compacting Concrete (SCC) ? Uses and Major.
What is GGBS? Properties, Benefits & Environmental Impacts
Measurement tape I use : Stanley.
The Safety shoes I use : Allen Cooper.
Calculation of Cement Quantity :-
The sum of M20 ratio (1:1.5:3)
= 1 + 1.5 + 3 = 5.5.
Volume of cement = (M20 cement proportion / sum of M20 ratio) × Dry volume
= ( 1 / 5.5 ) × 1.54
= 0.28 m³.
Weight of cement = volume × Density (Density of cement = 1440 kg/m³)
= 0.28 × 1440
= 403.2 kg
But cement comes in bags and weight of one bag is 50 kg.
Thus no. of bags = 403.2 / 50 = 8 bags.
Therefore, at least 8 bags of cement will be needed for M20 concrete per m³.
Calculation of Sand Quantity :-
Volume of sand = (M20 sand proportion / sum of M20 ratio) × Dry volume
= ( 1.5 / 5.5 ) × 1.54
= 0.42 m³.
Weight of sand = volume × Density (Density of sand = 1740 kg/m³)
= 0.42 × 1740
= 730.8 kg
Similarly, approximately 0.731 metric tonne of sand will be required for 1 cubic metre of M20 concrete.
Calculation of Aggregates Quantity :-
Volume of aggregate = (M20 aggregate proportion / sum of M20 ratio) × Dry volume
= ( 3 / 5.5 ) × 1.54
= 0.84 m³.
Weight of aggregate = Volume × Density (Density of aggregate = 1550 kg/m³)
= 0.84 × 1550
= 1302 kg
Similarly, approximately 1.3 metric tonne of aggregate will be required for 1 cubic metre of M20 concrete.
Quantity of Water for M20 concrete grade :-
As per IS code you can calculate water quantity with the help of water cement ratio, which is approximately between 0.35 and 0.55.
weight of water = 0.50 × 403.2
= 201.6 kg.
So required water to produce a 1 cubic metre of M20 concrete mix is approximately 202 litre.
Application of M20 Concrete Mix Ratio :-
The M20 grade of concrete is used for the light weight structures as it can not bear a heavy loads, following are some important uses of M20 grade concrete in;
1. Residential Buildings :
- M20 is often used in foundations for small to medium-sized residential buildings.
- It is commonly used in the construction of reinforced concrete columns and beams.
- M20 concrete is used in floor slabs, especially where moderate strength is required.
2. Commercial Structures:
- In commercial buildings, M20 concrete is used for constructing floors that need to support moderate loads.
- It is suitable for building staircases in commercial properties.
3. Road Construction:
- M20 grade concrete is used for making pavements, walkways, and driveways as they don’t require more strength compared to other heavy components.
- It is used for the construction of kerbs along roads and highways.
4. Retaining Walls:
- M20 grade concrete is used in the construction of retaining walls that hold back soil in landscaping and road projects. For the construction of basements it is used for the construction of RE walls.
5. Water Tanks:
- Water tank and small STP (sewage treatment plant) for residential buildings can be constructed with the M20 concrete ratio grade as it is suitable for the moderate strength.
6. Driveways and Pathways:
- In the residential or commercial projects where load comes on the pavement and walkways are less as compared to heavy structure, we can build these services based structure with the M20 grade concrete.
7. Tie Beam :
- Tie beam are used to tie the footing together to provide more strength to the foundation in case of earthquake and concrete used to build such components are M20 grade concrete.
Here you can also calculate the quantity of beam, slab or column for a rectangular shape.
Quantity of Concrete with Material for a given mix design :- Concrete Calculator.
I appreciate the practical advice you’ve given here.
Thank you for appreciating the work I do.