How to Determine Concrete Slump What is concrete slump? What tools do you need? What is the procedure to test concrete slump? Great questions. Let's break down the tools needed and the testing procedure step by step. May 19, 2021 Sakrete When people hear the term “slump,” most think about posture; think of concrete slump as "concrete posture." In technical terms, slump is a measured indication of the workability, or flow, of a mix. The drier the mix, the lower or “tighter” the slump. Conversely, the wetter or “looser” the mix, the higher the slump. Although it appears simple, the method for determining slump is a highly scientific, calibrated experiment—and one that can make a major difference in the outcome of your concrete project.