Compaction Factor Test-Concrete Technology lab

The compaction factor test is to determine the workability  of concrete

Compaction factor test
Compaction factor test

Compaction Factor Test

The compaction factor is defined as the ratio of weight of partially compacted concrete to that of fully compacted concrete.It shall normally to be stated to the nearest second decimal place.


Compaction factor apparatus


Hand scoop

A rod of steel



Place the concrete sample gently in hte upper hopper to its brim using the hand scoop and level it.Open the trap door at the bottom of the upper hopper so that concrete falls into the lower hopper.

Push the concrete sticking on its sides gently with the rod.Open the trap door of the lower hopper and allow the concrete to fall into the cylinder below.

Cut off the excess of concrete above the top level of cylinder using trowels and level it.Clean the outside of the cylinder.Weight the cylinder with concrete (w1).Empty the cylinder and then refills it with the weight of partially compacted concrete.

Empty the cylinder and then refills it with the same concrete mix in layers approximately 5cm deep,each layer being heavily rammed to obtain full compaction.

Level the top surface.Weight the cylinder with fully compacted concrete.This weight is known as the weight of fully compacted concrete (w2).Find the weight of empty cylinder.


Weight of cement=      kg

Weight of water=        kg

Weight of fine aggregate=      kg

Weight of coarse aggragate(10mm)=      kg

Weight of coarse aggregate(20mm)=      kg

Weight of admixture=      kg

Compaction factor calculation

Weight of empty cylinder=          kg

Weight of cylinder+partially compacted concrete=         kg

Weight of partially compacted concrete=        kg

Weight of cylinder+ Fully compacted concrete=          kg

Weight of fully compacted concrete=      kg


Compaction factor=      Weight of partially compacted concrete/Weight of fully compacted concrete

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