Suitability of Olokoro and Amaoba lateritic soil as pavement construction materials

Abstract

The suitability of Olokoro and Amaoba lateritic soil as pavement construction materials was investigated. Soil samples were collected from the borrow sites and were subjected to preliminary tests (natural moisture content, specific gravity, particle size analysis and Atterberg’s limits) and strength tests (compaction and California Bearing ratio, CBR). The liquid limit, plasticity index and plastic limit were found to fall into A-2-7 soil of AASHTO classification for Olokoro and A-2-6 AASHTO classification for Amaoba sample. The Olokoro sample has average value of the dry density as 1.87g/m3 and average optimum moisture content of 15.6%. Whereas Amaoba has average maximum dry density of 1.88g/m3 and average optimum moisture content of 16.1%. Both soils were found to have the same average specific gravity of 2.6 having liquid limit of 44 and 40 for Olokoro and Amaoba with plastic limit of 30 and 18, plasticity index of 14 and 22 respectively. Based on the CBR values 20.3% and 19.67% obtained from the two samples, the two lateritic soil will requires modifications to help improve their properties for use as sub base and base materials. However, both of the soil samples are good fill materials in road work contractions.