Elaboration of a Road Material Based on Clayey Soil and Crushed Sand

Abstract

To contribute to the enhancement of unconventional local materials used for road construction, this study char-acterizes a crushed sand 0/5, a clayey soil and the litho-stabilized material without and with hydraulic binder anddetermines their use in accordance with some reference specifications (CEBTP 1984). It is shown that the differ-ent components are not usable alone in pavement base. Indeed, the plasticity index obtained for the clayey soil is21%, a value higher than the imposed standards. In addition, the grading of the 0/5 crushed sand does not fitintothe range proposed by CEBTP. A combination of these two (02) components is therefore considered to obtain asuitable material usable for the sub-base. This new material does not enter any class of the CEBTP lateritic soils.In order to be used in base layer, a treatment with hydraulic binder is carried out with the intention to improve itsmechanical performances. The optimal dosage of hydraulic binder to achieve the desired mechanical performanceis obtained by studying the evolution of the mechanical characteristics of the mixture. After this treatment, theBearing Ratio index of the mix increases from 37 to 223 for the optimal dosage and the dry compaction densitydecreases from 2.11 to 2.06 g/cm3 while the optimal water content increases from 9% to 10.1%.