Assessment of black cotton soil (BCS) steadied with plantain peel powder (PPP) was investigated. BCS are said to be an extensive soil and mostly disposed to volumetric changes in moisture, because of the influence of mineral montmorillonite present in it, which has an extensive lattice. Various material has been used in the past to stabilize BCS but in this study, an attempt was made by stabilizing with plantain peel powder (PPP), the BCS was obtained from Yola, Adamawa state, Nigeria. The BCS was stabilized in (0, 2, 4, 6, 8, 10) % proportion respectively. To determine the Engineering properties of the BCS when stabilized with PPP, several laboratory tests, such as Grain Size Analysis, Natural Moisture Content, Linear Shrinkage, Specific gravity, Plastic Limit and Liquid Limit, which were all carried out in line with the British Standard code of practice. The laboratory preliminary tests on the soil results showed that the percentage passing sieve 200 is greater than 35% while Grain Size Analysis gave 26%, Natural Moisture Content 14%, Linear Shrinkage 14%, Plastic Limit 20% and Liquid Limit 48 % respectively.

The American Association of State Highway and Transportation Officials (AASHTO) and Unified Soil Classification System (USCS) classified the soils as A-7-5 which describe the soil as Clay of High Compressibility. The effect of PPP on the engineering properties showed that the LL %, PI % and Ls % varied between 48 and 32 for LL %, varied between 28 and 13 for PI % and varied between 14 and 7.5 for Ls % for (0, 2, 4, 6, 8, 10) PPP admixture which indicate that the higher the PPP the lower the clay content and the better the engineering properties examined. It was determined that with the mixing of PPP with the BCS, it enhances the engineering properties of the BCS sampled. Thus, Plantain Peel Powder (PPP) is suitable for stabilizing material for roadworks

Keywords: Admixture, Black cotton Soil, Engineering properties, Plantain Peel Powder, stabilization.