COMPACTION FACTOR TEST
Theory
The compacting factor test of cement concrete determines its workability, especially performed for concrete with low workability. This test helps engineers and construction workers ensure that the concrete used in a construction project is of adequate consistency and when poured and compacted will perform the work well.
IS 1199 2018 talks about the procedure of performing the test and IS 5515 talks about the apparatus specifications and its dimensions.
The compaction factor is basically the ratio of weights of partially compacted concrete to that of fully compacted concrete.
This test is used for concrete which has low workability, for which the concrete slump test is not suitable.
Just like the previous test, based on the values obtained of compaction factor, the degree of workability can be assessed along with the location where that degree of workable concrete can be suitably employed.
The primary purpose of this test is to determine how easily concrete can be placed and compacted, which is crucial for construction quality.
COMPACTION FACTOR TEST
APPARATUS SPECIFICATIONS
IS 5515 covers the requirements of the apparatus and accessories used for determining the compaction factor of fresh concrete with nominal maximum size of aggregates not exceeding 40 mm, as a measure of its workability.
Essential dimensions of the various component parts of the compaction factor apparatus is shown in the table below, where tolerances are not specified, the dimensions indicated are nominal.
The figure displays the apparatus used for performing the test whose dimensions are listed below-
| S. No. | PARTICULAR | DIMENSION (mm) | TOLERANCE (mm) |
|---|---|---|---|
| 1) | Upper hopper: | ||
| a) Top internal diameter | 250 | 2.5 | |
| b) Bottom internal diameter | 125 | 2.5 | |
| c) Internal height | 275 | 1 | |
| 2) | Lower hopper: | ||
| a) Top internal diameter | 225 | 2.5 | |
| b) Bottom internal diameter | 125 | 2.5 | |
| c) Internal height | 225 | 1 | |
| 3) | Cylinder: | ||
| a) Internal diameter | 150 | 1 | |
| b) Internal height | 285 | 1 | |
| c) Radius of bottom fillet | 20 | -- | |
| 4) | Distance between bottom of upper hopper and top of lower hopper | 200 | 1 |
| 5) | Distance between bottom of lower hopper and top of cylinder | 200 | 1 |
Other apparatus includes-
- trowels,
- hand scoop (15.2 cm long),
- a tamping rod of steel or other suitable material (1.6 cm in dia and 61 cm long rounded at one end),
- a weighing balance.