Effect of adding dune sand to tuff in Saharan road construction

The south region of Algeria is characterized by a wide surface, a scattered population and a very small ratio of road length per habitant. To allow the development of agricultural, industrial and touristic activities between different cities in the south of Algeria, it is necessary to maintain and to develop the road infrastructure. However the development of these infrastructures necessitates the use of huge amount of certified aggregates from quarries which is not available in the vicinity of the need. For these raisons, in the framework of sustainable development, a strategy which consists in using local materials like fine sediments (dune sand) and other types of material is engaged. The materials constituting the road layers, until today, have been limited to certain so-called noble materials (gravel, aggregates, etc.), but these are being depleted as a result of the intensive exploitation and the scarcity of quality careers. Gypso-limestone encrustation tuffs, the most used materials in pavements (base course and base course) in the Saharan areas such as southern Algeria, have shown acceptable behavior for many years until these last days, when this type of material begins to present certain limits under the effect of the intensity of the traffic. In order to promote the abundant wind sands in these regions, we are interested in developing the dune sands in the pavement as a mixture with the tuffs. The present work presents a contribution to the study of the behavior of the tuff of the Adrar region (South of Algeria) alone and mixed with the sand dunes in different formulations. The aim is to evaluate the evolution of mechanical properties including resistance to simple compression, the ability to compaction and punching (RBC). The work also discusses the influence of the addition of cement in low levels on the performance of the mixture.