Most of the laterites found in Ivory Coast do
not meet the technical conditions to be used in their natural state for the
design of road foundations. Also, to meet the growing needs for road materials,
various amendments are made to them, including litho-stabilization. Thus, this
study proposes to understand the influence of the granular class of natural
aggregates on the performance of laterites. To achieve this objective,
different proportions of crushed granites of class 0/5, 0/15 and 5/15 have been
incorporated into the soils of southern Côte d’Ivoire, especially in Samo. This
modified soil has been subjected to mechanical tests such as the modified
Proctor and CBR test. The results obtained show that the dry densities of the
incorporated laterites containing crushed granites increase with the content of
natural aggregates and decrease with the increase in the water content.
Likewise, the CBR bearing indices at 95% of the Modified Optimum Proctor of the
different compositions (laterites + crushed granites) increase with the
proportion of aggregates. The addition of coarse aggregates to the laterites
therefore promotes the establishment of a framework which improves its bearing
capacity. From 20% to 30% crushed granites respectively of class 0/15; 0/5 and
5/15, the values of the CBR obtained are greater than those of 30% therefore
these modified soils can be used as a foundation layer for traffic of T1, T2
and T3 type. Likewise, the laterites’ mixtures with at least 40% crushed
granites of class 0/15 and 0/5 can also be used for the foundation and base
layers.
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