Abstract
A comprehensive investigation of soil properties along the Abuja-Lokoja Road, focusing on samples A and B located between KM51 + 300 to KM51 + 200 and KM45+100 to M51+000 respectively utilizing site analysis, laboratory testing, and comparative analysis, the study identifies critical distinctions in soil composition and engineering behaviours. Sample A, classified as CH (clay of high plasticity), exhibits a moisture content of 12.6% and a density of 1.940 g/cc in contrast, Sample B, classified as GM (gravelly material), has a higher moisture content of 13.8% and a denser structure at 2.100g/cc. Despite differing compositions, both samples demonstrate comparable load-bearing capacities, reflected in California Bearing Ratio (CBR) values at 100% moisture content. Sample A records 32.7% (unsoaked) and 24.6% (soaked), while Sample B exhibits 32.7% (unsoaked) and 26.2% (soaked), indicating similar strength under specific moisture conditions. Further analysis reveals a slightly higher Liquid Limit (LL) for Sample A at 41% compared to Sample B's 40%, with closely aligned Plasticity Index (PI) values, suggesting comparable plasticity characteristics. These findings align with established trends in cohesive and gravelly soils from past research. Recognizing these distinctions is crucial for informed construction practices. The study recommends tailored engineering strategies, based on precise soil characterization, to optimize infrastructure performance and longevity in diverse soil environments. The emphasis on soil analysis and tailored engineering approaches underscores their significance in enhancing infrastructure stability and durability across varying soil conditions.

Key words: Road Failure, CBR, Abuja, Highway, Transport