The influence of water content on the Dynamic Cone Penetration Index of a lateritic soil stabilized with various percentages of a quarry by-product

Laterites and lateritic soils have been a source of good pavement material in tropical countries for a long time. However, increasingly it is becoming difficult to find lateritic material that meets the required specification within economic haulage distances of roads under construction. This has necessitated, among other things, the need for stabilization of lateritic soils of high fines content with quarry by-products. The use of such marginal material however requires that they be properly compacted in order to improve their engineering properties. For low volume roads there is the need for simple, rapid and economical methods of compaction quality control. This study builds upon previous ones on using the Dynamic Cone Penetrometer (DCP) for compaction verification and seeks to account for post-compaction water content changes. The use of the DCP for compaction verification starts with the establishment of a correlation between the Dynamic Cone Penetration Index (DPI) and the relative level of compaction. However, the DPI is sensitive to water content changes even at constant dry density. The objective of this study is to investigate how the DPI of a lateritic soil determined at the optimum moisture content changes when the water content varies and the fines content reduces. The results show that small changes in water content can lead to significant effects on DPI.