Characterisation of Lateritic Soil from Selected Locations along Ibadan – Oyo
Expressway for Highway Pavement Construction
*Osuolale, O. M., Raheem, A. A., Oluremi, J. R. and Adeosun, A. K.
Department of Civil Engineering, Ladoke Akintola University of Technology,
Ogbomoso, Nigeria.
*Corresponding author: Email: omosuolale@lautech.edu.ng
Telephone: +2348034435736
DOI:10.36108/laujoces/8102/10(0160)
Abstract
A good understanding of the engineering properties of lateritic soil is highly essential for effective use of the soil for highway pavement construction. The alarming rate of highway pavement failures within the study area has been attributed to paucity of information on the properties of the soil within the study zone. Therefore, the lateritic soils along selected locations along Ibadan – Oyo were characterised for their suitability for highway construction. Ten (10) lateritic soil samples were collected and they were labelled Trial Pit (TP) 1 to 10. The samples were subjected to the following laboratory tests: Sieve analysis, Liquid Limit (LL), Plastic Limit (PL), and Shrinkage Limit (SL), British Standard (BS), West African Standard (WAS), Modified AASHTO compaction and California bearing ratio. The samples were classified using AASHTO classification system. The results of the sieve analyses for percentage passing the 75 m ranged from 15.6 – 33.7%, LL, PL and SL ranged from 30.1 – 39.2%, 2.6 – 23.1%, and 2.1 – 9.3%, respectively. The maximum dry density (MDD) and optimum moisture content (OMC) for British, West African and Modified AASHTO compaction ranged from (1.48 – 1.94 g/cm’ and 10.40 – 16.40%), (1.69 – 2.40 g/cm’ and 9.60-14.40%) and (1.79 – 2.60 g/cm’ and 6.60- 11.60%), respectively. The ten samples are classified as A-2-6 soil. Based on the characterisation, all the samples are only suitable for fill and subgrade except sample TP2 that is also suitable for subbase and base course construction in highway pavement.
Keywords: California bearing ratio, Characterisation, Highway pavement, Lateritic soil, Liquid limit, Plastic
limit.