Investigation of the effects of fine dune sand on the geotechnical characteristics of lateritic soil

Lateritic gravels are highly favored as a construction material for road pavements in Africa. With the rise in road construction projects and subsequent increase in traffic and overloading, the required physical and mechanical properties of lateritic gravels have become more stringent. However, the desirable qualities of these materials are diminishing, and their exploitation will soon become an environmental problem. This study aims to enhance the physico-mechanical properties of the remaining lateritic gravels by incorporating fine dune sand sourced from Dori, in the Sahelian region in Burkina Faso. This lithostabilization was made by formulating mixtures with varying proportions of fine sand (10%, 20%, and 30% by weight). Then, the influence of sand content on the physico-mechanical behavior of lateritic gravels from two sites (Kamboinsin and Saaba) was examined. Results indicate a significant reduction in the plasticity index and an increase in optimal dry density with the addition of sand. Moreover, the California Bearing Ratio (CBR) index substantially improves, particularly with 30% sand content, making laterite from Saaba (LS) suitable as a base layer for road pavement according to CEBTP standards.