The slump test and compacting factor test are commonly used to assess the workability of concrete. These tests provide values that indicate the degree of workability of the concrete. The results obtained from the slump test and compacting factor test are critical in determining the workability of concrete.
Different types of concrete construction require varying degrees of workability, which can be determined through slump tests and compacting factor tests. These tests provide results that indicate the appropriate uses of concrete work based on the range of values obtained. The slump and compacting factor test values mentioned below are applicable to concretes with aggregates of either 20mm or 40mm maximum size.
| Degree of workability | Slump (mm) | Compacting factor | Use for which concrete is suitable | |
| Small apparatus | Large apparatus | |||
| Very low | – | 0.78 | 0.80 | Roads vibrated by power-operated machines. At the more workable end of this group, concrete may be compacted in certain cases with hand-operated machines. |
| Low | 25 – 75 | 0.85 | 0.87 | Roads vibrated by hand-operated machines. At the more workable end of this group, concrete may be manually compacted in roads using aggregate of rounded or irregular shape. Mass concrete foundations without vibration or lightly reinforced sections with vibration. |
| Medium | 50-100 | 0.92 | 0.935 | At the less workable end of this group, manually compacted flat slabs using crushed aggregates. Normal reinforced concrete manually compacted and heavily reinforced sections with vibration. |
| High | 100-150 | 0.95 | 0.96 | For sections with congested reinforcement. Not normally suitable for vibration, for pumping and tremle placing. |
| Very high | – | – | – | Flow table test is more suitable. |