Grades Of Concrete

What is Concrete Grades?

Concrete grades are denoted by M5, M 7.5, M10, M15 and so on.

Here, M denotes Mix design of concrete followed by compressive strength in N/mm2.

M is the proportion of ingredient which are Cement : Fine Aggregate: Coarse Aggregate.

For Example:
For M 20 grade concrete
       M = Cement : Sand : Aggregate
  So,M =      1      :  1.5   :     3
and 20 stands for Compressive Strength Of Concrete after 28 Days in N/mm2.

Concrete Grade & Mix Ratio

As per IS456:2000 less than M20 should not be used in RCC
CONCRETE	GRADES	RATIO	COMPRESSIVE STRENGTH (N/mm2)
Ordinary	M5	1:5:10	5
	M7.5	1:4: 8	7.5
	M10	1:3:6	10
	M15	1:2:4	15
	M20	1:1.5:3	20
Standard	M25	1:1:2	25
	M30	Mix Design	30
	M35	Mix Design	35
	M40	Mix Design	40
	M45	Mix Design	45
	M50	Mix Design	50
High Strength	M55	Mix Design	55
	M60	Mix Design	60
	M65	Mix Design	65