The TRL Dynamic Cone Penetrometer (DCP) Supplied by Laboratory Equipment Supplies is an instrument designed for the rapid in-situ measurement of the structural properties of existing road pavements constructed of unbound materials.
- The robust and simple design means that the DCP is quick and easy to use, portable and suitable for use in locations where access may be difficult.
- Correlations have been established between measurements with the DCP and conventional in-situ CBR so that results can be interpreted and compared with CBR specifications for pavement design.
- A typical DCP test takes only a few minutes and therefore the instrument provides a very efficient method of obtaining information which would normally require the digging of test pits.
Method of use:
- The 8 kg free fall hammer is lifted and dropped through a height of 575mm.
- The distance of penetration of the cone tip is then recorded and the cycle repeated.
- Continuous measurements can be made down to a depth of approx. 1000mm or when extension shafts are fitted to a maximum recommended depth of 2 meters.
- Where sub-pavement layers have different strengths, the boundaries can be identified and the thickness determined.
The Basic CBR Test:
- The California Bearing Ratio, believe it or not, was developed by The California State Highways Department.
- It is in essence a simple penetration test developed to evaluate the strength of road subgrades.
- This consists of causing a plunger of standard area to penetrate a soil sample, (this can be in the laboratory or on site).
- The force (load) required to cause the penetration is plotted against measured penetration, the readings noted at regular time intervals.
- This information is plotted on a standard graph, and the plot of the test data will establish the CBR result of the soil tested.
Reason for CBR Test:
- It sounds complicated, but the basis behind it is quite simple.
- We are determining the resistance of the subgrade, (i.e., the layer of naturally occurring material upon which the road is built), to deformation under the load from vehicle wheels.
- Even more simply put, ‘How strong is the ground upon which we are going to build the road’.
- THE CBR TEST IS A WAY OF PUTTING A FIGURE ON THIS INHERENT STRENGTH, THE TEST IS DONE IN A STANDARD MANNER SO WE ARE ABLE TO COMPARE THE STRENGTHS OF DIFFERENT SUBGRADE MATERIALS, AND WE ARE ABLE TO USE THESE FIGURES AS A MEANS OF DESIGNING THE ROAD PAVEMENT REQUIRED FOR A PARTICULAR STRENGTH OF SUBGRADE.
- The stronger the subgrade (the higher the CBR reading) the less thick it is necessary to design and construct the road pavement, this gives a considerable cost saving.
- We can also supply spares and repair your DCP.
- Our basic DCP kit comes complete with everything needed for a 1-meter test.
- Supplied with spanners, Allen key, weight & cone. (DCP test)
- Optional DCP extension rod enables the testing depth to be extended by 1 meter.
- 60° DCP cone
- 8kg DCP weight
- 575mm drop height
- Testing depth to 1000mm
- DCP Extension rods available for depths up to 2 or even 3 meters
- Portable and easy to operate
- DCP Tests can be carried out in minutes
- DCP Results correlate well with conventional CBR readings
- Our DCP is a Well proven, robust design
Due to the continuous development of our products, the goods supplied may vary in detail to that illustrated on this Website.