Grade of Concrete according to IS 456:2000

Grade of Concrete (IS code)

IS 456:2000, "Code of Practice for Plain and Reinforced Concrete," is the Indian Standard (IS) code used to specify the grades of concrete. For the design and building of reinforced concrete structures, this code is utilized.

A number is used to identify the various grades of concrete, followed by the letter "M," which stands for "Mix." The amount in megapascals (MPa) represents the concrete cube's typical compressive strength at 28 days.

Grade of Concrete	Concrete Mix ratio	Compressive Strength (Mpa-N/mm2)
Initial grades/Normal grades of concrete
M5	1:5:10	5
M10	1:3:6	10
M15	1:2:4	15
M20	1:1.5:3	20
Mid grades/Standard grades of concrete
M25	1:1:2	25
M30	Design mix	30
M35	Design mix	35
M40	Design mix	40
M45	Design mix	45
High strength concrete grade
M50	Design mix	50
M55	Design mix	55
M60	Design mix	60
M65	Design mix	65
M70	Design mix	70

 

Important points:

M5 / M7.5 = They are used in foundation beds to avoid direct soil contact with the foundation.

M10 = They are used in the construction of roads, levelling projects, and footing bases.

M15 = They serve as Plain Cement Concrete (PCC). They are employed in the construction of roads, levelling projects, and footing bases.

M20 / M25= They are utilized in Reinforced Cement Concrete (RCC). They are employed in the building of slabs, beams, columns, etc.

M30 / M35 / M40 = They should all be designed according to IS 10262-2009.

M45 / M50 = In general, runways, concrete roads, RCC columns, pressurized concrete girders, and pressurized beams employ M45 or M50.

M55 = M55 is identical to M45, however, it is solely used for piers and girders.

M60 to M80 =

• It is used for concrete of high-rise buildings, spillways of dams, long-span bridges etc.
• It can be used, where the environment is quite aggressive.

Based on the anticipated construction's load-bearing capability and structural requirements, the suitable grade of concrete is selected. When choosing the right grade of concrete for your particular project, always consult the advice of a civil engineer or follow to local building laws and standards.