The document describes the compaction factor test used to determine the workability of fresh concrete. The test involves using a compaction factor apparatus consisting of upper and lower hoppers and a cylinder to measure the density of partially and fully compacted concrete samples. The compaction factor is calculated as the ratio of the partially compacted density to the fully compacted density and can be used to determine whether the concrete has low, medium, or high workability.

1. B.) Compaction Factor Test
• To determine the workability of fresh concrete
• Use for low, medium and high workability concrete
• Test should be confirm to BS 1881 part 103
• Maximum size of aggregate will be 1.5”
• Test duration is 150 second from the commencement of test
• Determine by compacting factor apparatus
• Apparatus consist of one upper and one lower hoppers and
cylinder

2. • Compaction factor is the ratio of partial compaction to 100%
compaction
• To determine partial compaction fill the concrete in upper hopper
and open the bottom hinges of hopper so that the materials will
come in lower hopper
• Accordingly open the hinges of lower hopper so that the concrete will
come in cylinder
• Wipe unnecessary materials from the top of cylinder by float
• Determine the density of partially compacted concrete as “m1”
• Clean the cylinder and fill concrete with minimum 6 layers, 35 blows
each layer
• Determine the density “m2” of concrete so that it will be 100%
compaction density

3. Compaction factor will be as fallow
Compaction Factor= m1/m2
S.No Workability Compacting Factor Corresponding
Slump (mm)
01 Very low 0.78 0-25
02 Low 0.85 25-50
03 Medium 0.92 50-100
04 High 0.95 100-175