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how to make a slump test using a 12-inch-high
sheet metal cone that is open at both ends. The
bottom of the cone is 8 inches in diameter, and
the top is 4 inches in diameter.
Start the slump test by moistening the inside of
the metal cone. Then place the cone on a flat
smooth surface with the large end down and fill
it with concrete sample in three layers. Tamp
each layer before you add the next. After the
cone is completely full, lift the cone so the wet
concrete slumps down. Measure the height of
the concrete cone. Subtract this height from the
original 12-inch height to give the slump.
If the number is high, the concrete is a wet mix.
If it’s low, the concrete is a dry mix.
Recommended slumps for different types of
concrete work are shown in the chart below.
If the concrete is not thoroughly vibrated
(tamped), increase the values in the table by
50%.
However, the slump should never be more than 6
inches.