Question

According to i.S. 456 the number of grades of concrete mixes is

Answer 1

IS 456-2000 has designated the concrete mixes into a number of grades as M10, M15, M20, M25, M30, M35 and M40. In this designation the letter M refers to the mix and the number to the specified 28 day cube strength of mix in N/mm2.

Answer 2

Answer:

There are $7$ grades of concrete mix assigned by IS $456$.

Explanation:

• $M10, M15, M20, M25, M30, M35$ and $M40$ are the grades assigned by IS $456-2000$ to concrete mixes.

• The letter M indicates the mix, and the number denotes the specified $28-$day cube strength of the mix in $\frac{N}{mm^2}$.

• The mix proportions of classes $M10, M15, M20$ and $M25$ are about $(1:3:6), (1:2:4),$ $(1:1.5:3),$ and $(1:1:2),$ respectively.

A - Ordinary Grade $M10 -M20$

B - Standard concrete $M25- M55$

C - High strength concrete $M60-M80$

D - Minimum grade for concrete for plain and reinforced concrete in