Concrete requires monitoring by means of tests to ensure that
subsequent mixes are of the same consistency and this can be
carried out on site by means of the slump test and in a laboratory
by crushing test cubes to check that the cured concrete has
obtained the required designed strength.
The slump cone is filled to a quarter depth and tamped 25 times †
filling and tamping is repeated three more times until the cone is
full and the top smoothed off. The cone is removed and the slump
measured, for consistent mixes the slump should remain the same
for all samples tested. Usual specification 50 mm or 75 mm slump.
Refs. BS EN 12350-2 (Slump) and BS EN 12390-1 (Cubes)
Materials Testing