Slump / Slump Test

The slump test is a simple field test that measures how much a cone-shaped sample of fresh concrete settles, or "slumps," after the mold is lifted away. The result, measured in inches, is a quick field indicator of a mix's water content and workability.

A slump that's too high can signal excess water and reduced strength; too low can make the mix difficult to place and finish. Inspectors and ready-mix drivers commonly run a slump test at the point of delivery before a pour begins.