Economic Importance of Laterite Deposit in Oke-Oyi Area, Ilorin, Nigeria

Olatunji K.J.; Olota B.A.

Abstract

Two soil samples A and B were taken from Oke-Oyi, Kwara state, North Central, Nigeria. The water content of the samples are 5.8% and 6.5 for sample A and B respectively. This shows the variability in water table in the area. The specific gravities values are 2.7 and 2.78 for samples A and B, this is an indicator of inorganic soil. Grain size analysis show the laterite to be sandy gravels with excellent workability as construction material which can resist erosion. Soil sample A and B falls on the CL zone on plasticity chart, this implies that they are not permeable to water and useful for construction purposes. The compaction test result for sample A when compared at energies of standard and modified Proctor gives optimum moisture content of 15.0% and 15.0% respectively, and maximum dry densities of 1.80 g/cm3 and 1.83 g/cm3, while sample B when compacted at energies of standard and modified gives optimum moisture content of 15.0% and 15.0% respectively and maximum dry density of 1.83 g/cm3 and 1.79 g/cm3. Notwithstanding, the values obtained for the specific gravities, grain size analysis, Atterberg limits and compaction tests meet the requirements of soils to be used as construction material. The California Bearing Ratio (CBR) values for soaked and unsoaked when compacted at energy of standard Proctor and modified Proctor range from 2 to 5% for both samples which make them good for sub-base material. The deposit should be evaluated and processed for mining for appropriate purposes.