What is the relationship between slump and vibration effectiveness?

The relationship between slump and vibration effectiveness is influenced by the workability of concrete. When slump is higher, it indicates a wetter mix that flows more easily. This increased fluidity means that less force is needed during the vibration process to ensure that the concrete settles and fills voids in the formwork. Essentially, a higher slump provides better mobility of the concrete, allowing it to move and compact under lower vibration force.

In contrast, a lower slump indicates a stiffer mix, which may not flow as easily. Therefore, more force would be required to achieve the same level of compaction and settling under vibration as would be needed for a higher slump mixture. In this context, the explanation highlights how the physical properties of the concrete mix directly influence the effectiveness and force required for vibration.