Study of the improvement of laterites from Senegal by addition of sand

Mixing laterites with granular materials as sand or crushed materials is a way to improve their properties and make them suitable for use in road construction. This article reports experiments made on two laterites from Senegal, treated by adding sand. Their characteristics are compared with the 1972 CEBTP specifications for low traffic roads in tropical regions. Lithostabilisation aimed at decreasing the plasticity index, while preserving the CBR index and keeping the grading curve inside the limits specified for use in foundation or base layer of low traffic roads. The study showed that CBR index reaction to sand addition varies from a laterite to the other. Possible evolutions of CEBTP specifications to account for the experience of last decadres are discussed.