Grades of Concrete

Actually, what do we mean by grade of concrete.? Concrete grades are denoted by M10, M20, M30, according to their compressive strength. The “M” denotes Mix design of concrete followed by the compressive strength number in N/mm2, “Mix” is the respective ingredient proportions which are Cement: Sand: Aggregate Or Cement: Fine Aggregate: Coarse Aggregate.

Concrete Grade and Mix Ratio Table

As per IS 456:2000, the grades less than M20 should not be used in RCC works

Concrete Grade Mix Ratio Compressive Strength
MPa (N/mm2) Psi
Normal Grade of Concrete
M5 1 : 5 : 10 5 MPa 725 psi
M7.5 1 : 4 : 8 7.5 MPa 1087 psi
M10 1 : 3 : 6 10 MPa 1450 psi
M15 1 : 2 : 4 15 MPa 2175 psi
M20 1 : 1.5 : 3 20 MPa 2900 psi
Standard Grade of Concrete
M25 1 : 1 : 2 25 MPa 3625 psi
M30 Design Mix 30 MPa 4350 psi
M35 Design Mix 35 MPa 5075 psi
M40 Design Mix 40 MPa 5800 psi
M45 Design Mix 45 MPa 6525 psi
High Strength Concrete Grades
M50 Design Mix 50 MPa 7250 psi
M55 Design Mix 55 MPa 7975 psi
M60 Design Mix 60 MPa 8700 psi
M65 Design Mix 65 MPa 9425 psi
M70 Design Mix 70 MPa 10150 psi

Grades of concrete, mainly classified in three categories as follows 

1- Lean concrete

2- Ordinary grade of concrete

3- Standard grade of concrete

4- High strength concrete grades

1- Lean concrete

Lean concrete is a mix where the amount of cement is lower than the amount of liquid present in the strata.

M5 GRADE

Where M stands for Mix ration & 5 stands for  compressive strength of a 150mm cube after 28 days of curing, expressed in N/mm2

The mix ratio is  1:5:10 (1 Cement, 5 Sand and 10 Aggregate)

Application/use: –  To provide the uniform surface of the foundation concrete and to prevent the direct contact of foundation concrete from the soil.

M7.5 GRADE

The mix ratio is  1:4:8 (1 Cement, 4 Sand and 8 Aggregate)

Application/use: –  To provide the uniform surface of the foundation concrete and to prevent the direct contact of foundation concrete from the soil.

2- Ordinary grade of concrete

M10 GRADE

The mix ratio is  1:3:6 (1 Cement, 3 Sand and 6 Aggregate)

It is used as PCC (Plain Cement Concrete)

Application/use: – It can be used in the construction of Levelling course, bedding for footing, concrete roads, etc.

M15 GRADE

The mix ratio is  1:2:4 (1 Cement, 2 Sand and 4 Aggregate)

It is used as PCC (Plain Cement Concrete)

Application/use: –  It can be used in the construction of Levelling course, bedding for footing, concrete roads, etc.

M20 GRADE

The mix ratio is  1:1.5:3 (1 Cement, 1.5 Sand and 3 Aggregate)

It is used as RCC (Reinforced Cement Concrete)

Application/use: – It can be used in the construction of Slabs, beams, columns, footings, etc. (For mild exposure)

3- Standard grade of concrete

M25 GRADE

The mix ratio is  1:1:2 (1 Cement, 1 Sand and 2 Aggregate)

It is used as RCC (Reinforced Cement Concrete)

Application/use: – It can be used in the construction of Slabs, beams, columns, footings, etc.

M30 GRADE

It is used as RCC (Reinforced Cement Concrete)

Application/use: – It can be used in the construction of Slabs, beams, columns, footings, etc.

M-30 Mix Designs as per IS-10262-2009

M35 GRADE

It is used as RCC (Reinforced Cement Concrete)

Application/use: – It can be used in the construction of Slabs, beams, columns, footings, etc.

M-35 Mix Designs as per IS-10262-2009

M40 GRADE

It is used as RCC (Reinforced Cement Concrete)

Application/use: –  Pre-stressed concrete, slabs, beams, columns, footings, etc. GRADE- M45 RCC e.g. Runways, Concrete Roads (PQC), Pressurized Concrete Girders, RCC Columns, pressurized beams

M-40 Mix Designs as per IS-10262-2009

GRADE- M50

It is used as RCC (Reinforced Cement Concrete)

Application/use: –  Runways, Concrete Roads (PQC), Pressurized Concrete Girders, RCC Columns, pressurized beams

M-50 Mix Designs as per IS-10262-2009

GRADE- M55

It is used as RCC (Reinforced Cement Concrete)

Application/use: –  Pressurized Concrete Girders and Pier

4- High strength concrete grades 

M60 GRADE & M80 GRADE

It is used as RCC (Reinforced Cement Concrete)

Application/use:-

1- It can be used RCC work where high compressive strength is required such as high rise buildings, long span bridges, ultra-thin white topping etc.

2- Constructions in aggressive environment.

3- Spillways of dams, coastal construction of a passage for surplus water from a dam.

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