Question

What is the meaning of the designation 'M30' concrete suggested for a reinforced cement concrete work?

• A. The mix characteristic compressive strength of 150 mm size cube at 365 days is 30 N/mm².
• B. The mix characteristic compressive strength of 150 mm size cube at 28 days is 300 N/mm².
• C. The mix characteristic compressive strength of 150 mm size cube at 28 days is 30 N/mm².
• D. The mix characteristic compressive strength of 100 mm size cube at 28 days is 30 N/mm2.

Answer 1

Answer: (C)

The M30 refers the symbol M, used for the designation of concrete mix, refers to the mix and the number refers to the specified characteristic compressive strength of 150mm size cube at 28 days expressed in 30N/mm². • It is used in RCC, and construction of slabs, beams, columns, footing etc.