A laboratory procedure using the dynamic cone penetrometer for assessing the suitability of materials for low volume roads

Abstract

In order to minimise the cost of constructing low volume roads (LVRs), optimum use must be made of locally available, naturally occurring materials. However, conflicts often arise between material acceptability, as defined by conventional test methods and specifications, and material suitability in terms of actual engineering performance as a “fitness-for-purpose” road construction material. It is crucial to adopt appropriate test methods and specifications for selecting acceptable construction materials to avoid such conflicts. This paper presents a laboratory procedure using the Dynamic Cone Penetrometer (DCP) to assess materials' suitability for use in LVRs. This approach enables materials to be selected based on their “fitness-for-purpose”. It prevents suitable materials from being rejected based on one or other traditionally specified parameters not being complied with, even though their strength, as measured by the DCP penetration rate (DN value in mm/blow) of the soil, may be adequate. Investigations of the properties of a wide range of locally available materials that have been used successfully in the construction of LVRs have confirmed the validity of the materials evaluation framework.