WHAT IS GRADE OF CONCRETE?

 What is Grade of Concrete?

Grade of concrete is defined as the minimum strength the concrete must posses after 28 days of construction with proper quality control and curing processes. Grade of concrete is denoted by M to the desired strength in MPa or N/mm2. For example, for a grade of concrete with 20 MPa strength, it will be denoted by M20, where M stands for Mix.

Grades of Concrete

Regular grades of concrete are M15, M20, M25 etc. For plain cement concrete works, generally M15 is used. For reinforced concrete construction minimum M20 grade of concrete are used.

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