Slump flow value describes the flowability of a fresh mix in unconfined conditions. It is a sensitive test that will normaly be  spesified for all SCC, as the primary check that fresh concrete consistence meets the specification. Visual Observation during the test and/or measurement of the T500 time can give additional information on the segregation resistance and uniformity of each delivery.

The following are typical slump-flow classes for a range of applications:

SF1 (550-650 mm) is appropriarite for:

• unreinforced or slightyl reinforced concrete structures that are cast from the top with free displacement from the delivery point
• casting by a pump injection system
• section that are small enough to prevent long horizontal flow

Sf2 (660-750 mm) is suitable for many normal applications

Sf3 (760-850 mm) is typically produced with a small maximum size of aggregates (less than 16mm) and is used for vertical applications in very congested structure with complex shapes, or for filling under fromwork. SF3 will often give better surface finish than SF2 for normal vertical applications but segregation resistance is more difficult to control.