• The Dynamic Cone
    The Dynamic Cone
  • Penetrometer (DCP)
    Penetrometer (DCP)
  • in action as it is used
    in action as it is used
  • on construction sites.
    on construction sites.

DCP — Dynamic Cone Penetrometer  

RT Agencies supplies the South African made DCP
Dynamic Cone Penetrometer = DCP - Diagnosing Soil Compaction

  • The Dynamic Cone Penetrometer is essential for the testing of soil compaction and testing of soil strength and shear strength of soil.
  • The Dynamic Cone Penetrometer test goes into cell-tower site preparation.
  • The DCP testing is done before trenching and laying of fiber optical cables.
  • The DCP test is used on-site for soil density tests; no samples need to be taken to a laboratory
  • The Dynamic Cone Penetrometer is for geotechnical investigations to obtain information on the physical properties of soil and rock around a site.
  • The DCP test is used in preparation for the design of earthworks and  foundations
  • The DCP test is used to measure the resistivity of soils or backfill materials required for underground transmission lines, oil and gas pipelines.
  • The DCP test is carried out on site ( in-situ ) to determine CBR of soil
  • Cell Tower Site Preparation and Construction - DCP is used for soil compaction testing.
  • Trenching, Laying & Installation of Fiber Optical Cables - DCP is used for in situ density tests.
  • Cable Trenching, Pipe-Laying - DCP is used in Quality Control of  soil compaction.
  • Trench Reinstatement - Use of DCP to control compaction of granular fill.

In Roads design the DCP test is used for onsite measuring of road material strength. The DCP test provides an indication of a material’s in-situ resistance to penetration; it is used to estimate the subgrade strength. In road building the DCP test indicates that the material will be able to withstand higher wheel and axle loads before penetration into the surface occurs. If the DCP cone penetrates quickly into the soil, it indicates that the material has poor strength or insufficient compaction. Either thicker pavement layers might be needed or better compaction. The test results can be correlated with the California Bearing Ration (CBR) by applying a formula. It can save much time and money later by ensuring that the road is designed properly.

The hammer is 8 kilograms, fall distance is 575 mm and the tip/cone is 60°.
The DCP Dynamic Cone Penetrometer tester has four unit parts.   • 1. 8 kg Hammer,  • Upper Rod,  • 900 mm Ruler,  • Bottom Rod.

The long steel rod with a standard sized hardened steel cone is at the penetrating end. Its length is approximately one metre, but it can be extended by one metre extension rods. At the upper end of the steel bar is a captive weight surrounding the rod, this weight is able to fall freely through a given drop height to achieve a standard amount of penetrative effort at every drop. By measuring the penetration of the cone against the number of drops of the weight it is possible to plot resistance to penetration and indirectly the strength / compaction of the layer being tested.

Made in South Africa!

There are a few schools of thought about where the Dynamic Cone Penetrometer also called the DCP test originated from. The Dutch and Australians claim that they are the inventors of the Falling Weight Penetrometer (DCP). The CSIR has nearly perfected it.

The DCP sold by RT Agencies is a wholly South African Product!

Manuals download section: DCP Manual & 'Use & Interpretation of the DCP test (CSIR, Pretoria)

Teaching videos about how to use the DCP

DCP - Dynamic Cone Penetrometer


A more technical description of the DCP:

The DCP works by using a 8 kg steel mass dropping 575 mm which hits the anvil. Each stroke causes penetration of a 20mm diameter cone (60° vertex angle) which sits at the base of  assembly into the soil (underlying surface)

The ST6 technique for using the Dynamic Cone Penetrometer describes the rate of penetration of the DCP into a natural or compacted material (soil) with the help of the dropping weight (hammer). The penetration rate of the cone of the DCP is inversely proportional to the resistance level of the terrain. The DCP test is an in-situ CBR or density testing of the soil.

The DCP is useful in  assessing the density of a fairly uniform material by relating density to penetration rate (DN). Using this method under-compacted or "soft spots" of the Subgrade can be identified. The test is designed to evaluate the situ sturdiness substance. Compaction degrees of pavement subgrade are determined by means of in-place density testing. - The DCP can efficiently be applied in quality control of granular base layer compaction as well as during backfill compaction of pavement drain trenches.

It is possible to obtain an approximate CBR figure from the results of using this equipment by applying a simple formula. It is a guideline not a benchmark figure, but still useful to know that you are 90% correct.