Compaction Factor Test:

Compaction factor test is more efficient and precise in determining the workability as compared to slump test. This test is more appropriate for the concrete mixes of very low workability that is commonly compacted through vibration. For such types of concrete mixes, it is hard to measure the workability by slump test, as they do not give any slump. This test is generally designed to test the workability of concrete mix in the lab but it can also be used at sites. Figure 4 shows the schematic set up of the apparatus used for carrying out this test.

In this test, the workability is measured by determining the degree of compaction achieved by a standard amount of work done for compaction of concrete by allowing the concrete to fall through a standard height from hopper 'A' to hopper 'B' and hopper 'B' to cylinder 'C'. The degree of compaction achieved through this test is called the compaction factor. Degree of compaction (i.e. compaction factor c.f.) is determined by determining the ratio of two densities, i.e. density of concrete achieved through this test and the density of the same concrete after full compaction.

Figure: Compacting Factor Test Apparatus