Mor DIOP^1,, Djibril SOW¹, Astou DIOKHANE¹, Mory COULIBALY¹

With a view to improving road materials, particularly low-bearing-capacity laterites, fly ash and cement are effective binders for enhancing their geotechnical and mechanical properties. This study aims to valorize low-bearing-capacity laterites for use as base courses in the construction of high-performance pavements. To this end, a laterite from the quarry located in the village of Thianguel, in the district of Oréfondé (Matam Region, northeastern Senegal), was treated with 4% silico-aluminous fly ash from the Senegal Chemical Industries (ICS) in Mboro and CEM II/B-LL 32.5R Portland limestone cement manufactured by Dangote Cement Senegal S.A. The methodology adopted is based on an experimental study of mixtures of laterite, fly ash and cement. Geotechnical laboratory tests were conducted to evaluate the influence of these additives on the physical and mechanical characteristics of the material. The results show a significant improvement in the performance of the treated laterite. The mixture containing 4% fly ash and 5% cement exhibited the best performance, with the CBR index increasing from 52 for the raw laterite to 252 after treatment. These results confirm the technical feasibility of this stabilization method. The combined use of local laterite, fly ash, and cement constitutes a sustainable, economical, and environmentally friendly solution, providing a relevant alternative to conventional soil stabilization techniques and contributing to the development of more efficient road infrastructure in Senegal.

Improvement, fly ash from the Mboro ICS, CEM II/B-LL 32.5Rt, CBR index, high-performance pavement, Thanguel laterite