Dynamic Cone Penetrometer
The Dynamic Cone Penetrometer (DCP) is an instrument which can be used for the rapid measurement of the in situ strength of existing flexible pavements constructed with unbound materials, to establish soil strength at depths from 800mm to 2 meters below ground level, it can also be used to determine the differing layer thickness of materials below ground level.
Measurements can be made down to a depth of 800 mm or to a maximum depth of 1500mm by adding an extension rod. Where the pavement layers have different strengths,the boundaries between them can be identified and the thickness of each layer determined using the software program called UK DCP 2.2.
Method
The DCP uses an 8kg weight being dropped through 575mm on to an anvil which in turn forces a small steel cone through the material, the penetration of the cone depends on the hardness of the ground being tested.
In some cases up to 10 blows of the weight will be needed to move the cone only 5mm but in other materials the cone could move up to 100mm with just 1 blow of the weight. During the test the number of blows and the Relating penetration is recorded.
The information recovered can now be analyzed and reported.