Influence of the Treatment of Bingerville Clayey Sands with a Batard Binder Mixture (Lime-cement) for Use in Road Engineering

In tropical countries, clay soils used in construction have unfavorable geotechnical properties and degrade prematurely due to their low bearing capacity and sensitivity to water, such as those of Bingerville, in southern Cote d'Ivoire, where these soils are the raw material for infrastructures projects. The use of improvement techniques such as treatment with hydraulic binders can improve the geotechnical properties of these soils by increasing their physical and mechanical strength in many countries where these materials are abundant, thereby reducing material transportation costs and environmental pollution. This study characterizes the clay soils of Bingerville in their natural state for their identification and suitability for treatment before subjecting them to lime and cement mixtures. The results of this study showed that the clay soils of Bingerville are clayey sands. After analysis, they are suitable for mixed treatment (lime-cement) in order to increase their geotechnical properties for their use in road techniques. Laboratory tests identified an optimal mixture of 3% lime and 6% cement. The experimental results made it possible to obtain, on clayey soils in the initial state, the total organic matter content (TOC), equal to 0.15%, a very low value, less than 1%, showing that these soils can support any load without deforming under the influence of water, therefore suitable for binder treatments. The plasticity index (PI) equal to 23.7%, a value greater than 12%, suggests that these clayey soils are subject to mixed Batard treatment (lime-cement). After treatment of Bingerville clay soils with lime and cement mixtures, dry densities increased from 1.83 to 2.03, with the 95% California Bearing Ratio (CBR) of the Modified Optimum Proctor (MOP) at 4 days of immersion increasing significantly from 14 to 94. These results are consistent with the recommendations for their use as treated local soils in low to medium traffic road projects.