Sustainable compaction methods for road infrastructure subgrades in water-scarce regions

Arid regions tend to lag behind in terms of economic development, especially with regard to road infrastructure. This infrastructure is essential for improving connectivity and supporting local development. The main reasons for this are the scarcity of water resources, which poses a significant challenge to such projects, and the unavailability of suitable materials. In this context, it is essential to implement techniques adapted to water scarcity and to use local materials in order to ensure that the work is carried out to standards comparable to those achieved under optimal conditions. This study investigates the improvement of soil compaction under low moisture conditions by increasing compaction energy and incorporating fine materials while varying gravel content. The compaction parameters of the local materials are examined using the California Bearing Ratio (CBR) and the Proctor tests and then compare them with the parameters obtained at optimum water content. The results indicate that increasing compaction energy improves both maximum dry density and CBR values for certain materials. For others, the addition of fine materials resulted in a 16% increase in maximum dry density and a fourfold increase in CBR values. Combining gravel and powder additives applied to loose soils resulted in a high maximum dry density and a fivefold increase in CBR values. Overall, increasing compaction energy, as well as the combined effect of incorporating fine materials and optimizing the gravel, provides an efficient and cost-effective solution for pavement construction in water-scarce environments.