Investigation of the Suitability of Subgrade Soils for Road Pavement Development in Federal University Lokoja, Felele Campus

The quality of any road depends on the type of soil that serves as the subgrade for road construction. This study aims to investigate the suitability of sub-grade soils within the study area to support the loads that the proposed campus roads will carry. Subgrade soil samples were collected and tested in the laboratory for the following geotechnical tests: sieve analysis, Atterberg limit tests (liquid limit and plastic limit), compaction test, and California Bearing Ratio (CBR) test. The results obtained were compared with standard references and used for interpretation. The result from the sieve analysis showed that the percentage passing sieve number 200 (0.075mm) for the study area is less than thirty-five percent (<35%). The liquid limit (LL), Plastic limit (PL), and Plasticity index (PI) value ranges from 32.2% to 34.4 %, 19.8% to 21.1%, and 12.0% to 14.65% respectively. The moisture content value ranges from 12.1% to 14.3%. The optimum moisture content (OMC) and maximum dry density (MDD) value ranges from 17.2% to 19.2% and 1849kg/m3 to 1913kg/m3. The CBR value for Unsoaked ranges from 18%-22% while that of soaked ranges from 8%-13%. The values for all the geotechnical parameters investigated revealed that the soil in the study area is suitable to be used as sub-base and base fill materials in road construction.