Appropriate and efficient maintenance of low cost rural roads. Report 4: Field trials using the modified DCP apparatus.
This element of the project was concerned with the evaluation and development of a pavement and material assessment apparatus in the context of low cost rural feeder roads in developing countries. It was firstly necessary to select an appropriate piece of equipment and then modify it. After initial investigation work, the Dynamic Cone Penetrometer (DCP) was chosen as the equipment to be modified for assessment of roads in-situ and of aggregate materials at source, this is discussed in Report 3.
Roughton International was able to trial the new equipment on a detailed pavement evaluation project in Malawi. Pavement characteristic data from peak deflection measurements, radius of curvature measurements, and full deflection bowl measurements and routine dynamic cone penetrometer tests were conducted on a variety of pavement types throughout the country.The Stiffness (Resilient Moduli) of the materials is calculated from the pavement investigations and a comparison made against the parameters calculated by the work described in Report 3, and previous common relationships developed by the Transport Research Laboratory. In general, the relationships described in Report 3 performed well against the TRL relationship.
In summary, the DCP with the newly formed relationship performed well, and with further development work and investigation could realise significant time and effort costs in obtaining the Stiffness (Resilient Modulus) parameter for pavement design, and hence pavement life.