The purpose of this standard is to define the specifications and conditions of use of water-reducing/fluidifying additives that can be used in the manufacture of concrete, mortars and pastes, as well as to establish the criteria that must be applied to determine the characteristics both of these additives, and of the pastes, mortars and control and reference concretes (both made with the control materials and - in addition - with the additive that will be tested in the reference pastes, mortars and concretes).