ROAD

This project was a detailed investigation on the properties of subgrade soils used in the construction of Warri-Sapele road in South South, Nigeria. Subgrade samples were collected at nine (9) different spot by doing auger borings examinations on the spots that are observed to have failed or are failing at about 5 and 10 meters away from the tarred road at one side. The samples were subjected to the following laboratory tests; Compaction test, California bearing ratio (CBR). According to O'Flaherty the range of value anticipated using standard proctor test method are MDD and OMC which range from 1.72g/cm3 to 1.84g/cm3 and 8.88% to 12.70% respectively, therefore the results indicated that all the samples were sandy clay in texture. The CBR values for the top unsoaked and soaked samples of the subgrade soil range from 21.9% to 37.5% and 5.0% to 26.1% respectively while bottom unsoaked and soaked range from 17.9% to 51.5% and 9.3% ((P2R3, Sapele) to 37.3% respectively. Therefore, the CBR test results obtained conform to the Federal Ministry of Works and Housing which confirmed that the subgrade sample materials are suitable for road construction except for subgrade materials P2R3 collected from Sapele which however can be stabilized to meet the standard requirement before being used .These data obtained from the analysis can be useful by civil engineers in the design and construction of the study area for maximum durability.