Standard Consistency of Cement

Standard consistency is the percentage of water (by weight of cement) needed to produce a paste of a defined penetration resistance, measured using the Vicat apparatus with its plunger attachment. Trial pastes are mixed at increasing water percentages until the plunger settles to the specified depth.

This value is not used directly in construction, but it is the essential first step for the setting-time and soundness tests, both of which are run on paste mixed to standard consistency.