# [2019] Grades of Concrete | Types | Concrete Mix Ratio Table

## Grades of concrete

**Grades of concrete**are related to compressive strength and composition of concrete. Various types of concrete grades are available in Civil Engineering.

GRADES OF CONCRETE |

- Can you perfectly define the term"
**grades of concrete**"? - How many grades of concrete are there in
**civil engineering**? - What do you mean by
**M30 concrete**? - What does
**"M"**represent in M30 concrete? - What is the difference between
**M30**and**C30**grades of concrete? - What is the
**concrete mix ratio**for different types of concrete grades?

### What is meant by "Grades of concrete"?

As a civil engineer, you may have noticed the term "Grades of concrete" or "M20 concrete" many times.

###

Maybe you could have ignored the term or you don't have detailed knowledge about 'Grades of concrete'.

Hey! don't worry, here I shared everything that a civil engineer must know about "Grades of concrete".

Let's start together.

__Grades of concrete__represent the strength of concrete.

More specifically it represents that the compressive strength of a 15cm concrete cube sample after 28 days of curing.

'Grades of concrete' not just define the

**compressive strength**but also define the**concrete mix**ratio or**composition of concrete**.
Hold on, everything will be explained thoroughly.

Okay, let's back to the point.

This Grade of concrete denoted by prefixing and followed by the number.

Example: M10, M15, M20, M30, etc...

Where

Where

**M**is prefixing and is stand for**"MIX".**
Similarly, 10, 15, 20, 30 are the number used to denote the compressive strength in

**N/mm2.**

Now we can easily conclude that meaning of

__M30 grade of concrete.__

**M30 GRADE OF CONCRETE →**

"Minimum compressive strength of a 15cm concrete cube is 30 N/mm2 after 28 days of curing.

One thing you should keep in mind that Grade of concrete can be denoted by M20 as well as C20.

As per Indian standard "M" is used to denote the grade of concrete. Similarly 'C' is generally used by British standard.

Well, there is one more major difference.

Let me explain through an example.

"C20"- characteristic strength of

__concrete cylindrical sample__(15 cm dia* 30cm of height) after 28 days of curing.
"M20"- characteristic strength of

__concrete cube__(15 cm cube) after 28 days of curing.
Yes, the main difference is based upon the type of sample used in each standard.

In the case of British standard, the cylindrical concrete sample is used whereas Concrete cube sample is used for Indian standard.

Okay, till now we have defined the meaning of grade of concrete.

Now let's move forward.

You may like: Application of Grades of concrete

###
__Concrete Mix ratio table__

I already mentioned above that the grades of concrete also define the composition or mix-ratio of concrete.

And we have recently covered that specific grade of concrete gives us a specific amount of compressive strength.

For an Example, M10 concrete has a strength of 10N/mm2.

But the question that arises is '

__How can we determine the mix ratio of concrete from the grade of concrete'?__

Well, The Indian standard

**(IS CODE-456:2000)**has given us a table from where we can figure out the proportion of cement, fine aggregates, and coarse aggregate.

CONCRETEGRADE | MIX RATIO | CHARACTERISTIC-COMPRESSIVESTRENGTH OF CONCRETE |

M5 | 1:5:10 | 5 N/mm^{2} |

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 |

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 |

M55 | DESIGN MIX | 55 N/mm2 |

M60 | DESIGN MIX | 60 N/mm2 |

M65 | DESIGN MIX | 65 N/mm2 |

M70 | DESIGN MIX | 70 N/mm2 |

M75 | DESIGN MIX | 75 N/mm2 |

M80 | DESIGN MIX | 80 N/mm2 |

As per Indian standard, there are three major groups of concrete such as

- ordinary concrete (M10, M15, M20)
- standard concrete (M25, M30, M35, M40, M45, M50, M55)
- high-strength concrete (M60, M65, M70, M75, M80)

As you can see each grade of concrete represent some specific mix ratio (only for

__nominal mix__).
For an example, M20 grade of concrete defines a mix ratio of

**1:1.5:3**which means for every 1 part of cement, 1.5 part of sand and 3 part of coarse aggregates is mixed.
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In concrete technology, there are two types of mixes available-

- Nominal mix.
- Design mix.

Nominal mixes are those whose mix ratio is pre-defined which includes grades of concrete up to M25.

Nominal mix-M5, M7.5, M10, M15, M20, M25.

While further breakdown, we can say that the proportion of cement, sand, and coarse aggregates of concrete grade up to M25 are already defined and constant.

Nominal mixes are adopted for the small scale of construction work where the required amount of concrete is not so high.

The nominal mix ratio of different grades of concrete is shown below-

NOMINAL MIX RATIO OF CONCRETE UP TO M25 |

Similarly, Design mix is those whose mix ratio proportion is obtained from the various lab test.

Design mix- M30, M35, M40, M45, M50, M55, M60, M65, M70, M75, M80.

Here one thing you must remember that the mix proportion of cement, sand and coarse aggregates are not predefined.

This mix proportions can be obtained by the various lab test.

These proportions can be vary depending upon many Factor such as the

__process of concreting__**,**__properties of concrete__**,**__quality of the material__**,****etc.**
A large type of construction work highly depends on the design mix of concrete where high strength is the first priority.

Comment below if you still have any unanswered question. Feel free to share.

That's all information regarding Grades of concrete.

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[2019] Grades of Concrete | Types | Concrete Mix Ratio Table
Reviewed by Civil049seminar
on
January 27, 2019
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