Improving the Adhesion of Bituminous Concrete by Adding Dune Sand—An Algerian Case Study

In the Saharan regions of Algeria, locally available aggregates often exhibit inadequate resistance to shock, attrition, and polishing, which limits their suitability for pavement wearing courses. Standard tests, including Los Angeles (LA), Micro-Deval (MDE), and Polished Stone Value (PSV), confirm their inability to meet national specifications. This study investigates the potential of incorporating dune sand, an abundant local resource, to enhance the mechanical and surface performance of asphalt mixtures. Laboratory tests were carried out using the Wehner and Schulze device to evaluate skid resistance, alongside conventional mechanical evaluations. The results demonstrate that the addition of dune sand generates a beneficial microtexture that increases friction and reduces polishing susceptibility. Optimal performance was achieved with incorporation rates between 10 and 20%, which not only improved skid resistance but also enhanced the stiffness and durability of the mixtures. These findings highlight the dual benefits of valorizing dune sand: improving road safety through better surface performance and promoting the sustainable use of local materials in Saharan road construction.