What method of consolidation should be used when the slump is less than 1 inch?

When the slump is less than 1 inch, this indicates that the concrete mix is quite stiff and less fluid. In such cases, vibration is the most effective method of consolidation. Vibration helps reduce air voids and ensures thorough compaction of the concrete, allowing it to fill the forms completely and settle into place without leaving gaps or voids. The use of vibration in stiff mixes promotes better bonding between aggregates and the cement paste, enhancing the overall integrity of the cured concrete.

While rodding, stamping, and floating have their applications, they are generally more suited for concrete with higher slumps. Rodding is typically used for more fluid mixes to facilitate consolidation, while stamping and floating are techniques more aligned with finishing and leveling rather than achieving adequate consolidation in stiff mixes.