Analysis of Lateritic Soil Reinforced with Palm Kernel Shells for Use as a Sub-Base Layer for Low-Traffic Roads

Abstract

In tropical areas, palm oil production generates significant amounts of waste, including palm kernel shells. The use of this waste in the civil engineering sector, presents a very challenging task. In the present study, the production of lateritic soil (A-2 in GTR classification and A-7-6 (9) in HRB classification) reinforced with palm kernel shells is considered. In order to improve their performances, these materials are mixed using the Fuller’s parabolic law. Moreover, experimental tests are used to characterize the physical and mechanical geotechnical properties of the lateritic soil. After characterizing the matrix (i.e., lateritic soil) and the inclusions (i.e., palm kernel shells) in their natural state, it is found that Avrankou’s lateritic soil has a high level of fine particles (56.6%), high plasticity (PI = 21%) and low lift (ICBR = 17%); which makes it unusable in the pavement layer. Results also prove that the mixture composed of 39% of lateritic soil volume and 61% of PKS with a CBR index equals to 30 and the mixture composed of 45% of lateritic soil, 40% PKS and 15% of lagoon sand with a CBR index equals to 41 can be used as sub-base layer for roads for low and medium traffic, respectively.