What is the meaning of the designation ‘M30′ concrete suggested for a reinforced cement concrete work? Mark as favorite Copy Link The mix characteristic compressive strength of 100 mm size cube at 28 days is 30 N/mm². The mix characteristic compressive strength of 150 mm size cube at 365 days is 30 N/mm². The mix characteristic compressive strength of 150 mm size cube at 28 days is 300 N/mm². The mix characteristic compressive strength of 150 mm size cube at 28 days is 30 N/mm². Check Answer