It is undeniably true that the mixing ratio of the compact material offers good workflow and finishing for the structure. It has different applications and ratios to get the desired durability and strength. This essay will discuss the types, applications, benefits, and mixing table of concrete mix.
What is the Concrete Mix Ratio?
The primary ingredients of the compact material include cement, sand, and stone or gravel. It is a process that involves mixing the required components at different proportions. It provides the inherent benefits of strength, durability, safety, and affordability for the structures built. This mixture often requires a longer setting time than cement alone. But it can be configured into other forms for better outcomes.
According to the project requirements, the proportion of the mixture can be changed. Cement acts as a glueing material that binds the concrete mixture. It is suited for building versatile and attractive structures that solve the needs of the construction industry. This article gives details on the types and benefits of concrete mixes.
Types of Concrete Mix Ratio
Concretes are mixed in different proportions according to the construction requirements. They are as follows:
Nominal Mix Concrete
In the actual concrete mix, the proportions for the compact materials are predefined. Minor construction projects can use this mix.
The table below will provide the distributions of nominal concrete mix.
S.No | Concrete Grade | The total quantity of dry coarse materials by mass per 50 kg of cement | Different proportions of fine and coarse aggregate | The amount of water per 50 kg of cement |
1 | M5 | 800 | The general ratio is 1:2, but for the upper limit, 1:1.5, and for the lower limit, 1:2.5. | 60 |
2 | M7.5 | 625 | 45 | |
3 | M10 | 480 | 34 | |
4 | M15 | 330 | 32 | |
5 | M20 | 250 | 30 |
Standard Concrete Mix
The standard proportion of concrete mix used for building superstructures is 1 part cement, 2 parts sand, and 4 parts gravel or stone. The standard concrete mix comes under the grades M25 to M50.
High-Strength Mixes
The high-strength compact material comes under the grades M55 to M70. Special infrastructures like reservoirs, highly elevated buildings, and bridges require high-strength compatible materials to increase their durability and strength. It can also reduce high permeability in concrete.
Design Mix Concrete
After analysing the properties of ingredients, the engineer can determine the mix ratio of the concrete. The ratio can be fixed according to the project requirements. In this process, different additive materials can also be added to attain perfection.
Concrete Proportioning Methods
Different methods are used to determine the proportion of the concrete mix. They are as follows:
Arbitrary Method
In the arbitrary method, the proportions of concrete mix – cement, sand, gravel, or stone, are chosen randomly. They can be adjusted with water as per the construction requirement.
S.No | Construction Work | Concrete mix ratio |
1 | For foundations and mass concrete work | 1:4:8 |
2 | For normal concrete processes | The defined proportions are 1:1.5:3 and 1:2:4. |
3 | For high-strength concrete work | The ratio is 1:1:2. |
Fineness Modulus Method
The proportional sizes of the coarse and fine aggregates can be determined using the fineness modulus (FM) method. The aggregates must comply with Indian standards. As per the Indian standard, the sizes of the coarse aggregates are 80 mm, 40 mm, 20 mm, 10 mm, and 4.75 mm. The IS sieves for fine aggregates are 1 mm, 600 μ, 300 μ, 212 μ, 150 μ, and 75 μ. The simple formula for deriving the fineness modulus is as follows:
P = [(X-Y)/ (Y-Z )]x 100
Where, X = FM of coarse aggregate
Y = FM of fine aggregate
Z = FM of combined aggregate
S.No | Particle size (mm) | Fineness modulus | Average FM | |
Maximum | Minimum | |||
1 | 20 | 4.7 | 5.1 | 4.90 |
2 | 25.4 | 5.0 | 5.5 | 5.25 |
3 | 31.5 | 5.2 | 5.7 | 5.45 |
4 | 38.1 | 5.4 | 5.9 | 5.65 |
5 | 40 | 5.7 | 6.3 | 6.00 |
6 | 80 | 6.5 | 7.0 | 6.75 |
Maximum Density Method
This method is applicable when the concrete mix is caused by determining its aggregates in a way that the heaviest weight for the same volume involves dense concrete.
Concrete Mix Ratio Table
The below table will comprise the ratios of concrete mixes and their compressive strengths.
S.No | Types of Concrete | Grades of concrete mix | Concrete mix ratio | Compressive strength |
1. | Nominal concrete | M5 | 1:5:10 | 5 N/mm2 |
M7.5 | 1:4:8 | 7.5 N/mm2 | ||
M10 | 1:3:6 | 10 N/mm2 | ||
M15 | 1:2:4 | 15 N/mm2 | ||
M20 | 1:1.5:3 | 20 N/mm2 | ||
2. | Standard Concrete | M25 | 1:1:2 | 25 N/mm2 |
M30 | Design Mix | 30 N/mm2 | ||
M35 | Design Mix | 35 N/mm2 | ||
M40 | Design Mix | 40 N/mm2 | ||
M45 | Design Mix | 45 N/mm2 | ||
M50 | Design Mix | 50 N/mm2 | ||
3. | High strength Concrete | M55 | Design Mix | 55 N/mm2 |
M60 | Design Mix | 60 N/mm2 | ||
M65 | Design Mix | 65 N/mm2 | ||
M70 | Design Mix | 70 N/mm2 |
Engineers or builders always prefer nominal concrete for M20 concrete grade.
Benefits of Accurate Concrete Mix Ratio
The proper mixture of the compact material with the right proportion increases the capacity and strength of the concrete poured into the building structure. Some points include:
Durability and Strength of Structure
The accurate ratio of the compact material provides the strength and durability of the structure. It can withstand heavy loads without causing any cracks or damage to the structure. It can also be resistant to natural disasters, thus increasing the durability of the structure.
Cost-Effectiveness
The required ingredients are measured easily and avoid creating waste. It can also depend on the type of concrete you are using, the project size, and the pricing and transportation of the local company.
Reduced Risk of Failure
The proper mixing, curing, and reinforcement of concrete in construction reduces the risk of failure in building structures.
Conclusion
A well-predefined concrete mix contributes to the success of any construction project. You must choose a strong, high-quality, and cost-effective concrete mixture for better outcomes. Qualified construction professionals may identify the right proportion of concrete mix. They are strong in their construction knowledge and ensure standard mixing processes for delivering high-quality structures.