STRENGTHENING OF BLACK COTTON SOIL AS SUBGRADE FOR RURAL RAOD CONSTRUCTION USING CRUSHED WASTE TILES.

ABSTRACT Black cotton soils are highly problematic due its ability undergo large changes in volume with variation in the moisture content. It has a peculiar characteristic of high plasticity, excessive swelling, shrinkage and low strength when wet, and is regarded unsuitable for construction material, (tare, Singh, & meShram, 2018). The black cotton soil sample used in this research work was obtained from Damaturu Local Government Area of Yobe State. The top soil was removed to a depth of 300mm before the soil sample to be collected by disturb sampling, sealed in plastic bags and put in sack to avoid loss of moisture during transportation. The samples were air dried in the laboratory before pulverizing. This study conducted an experimental study on the black cotton soil. Black Cotton Soil of 10%, replacement, 15%, 20% using crushed waste tiles were formed and a Compaction test, Atterberg limit CBR Test and sieve analysis was carried out on the replacements. The strength of the black cotton soil was improved. Significant percentage increase in strength was observed, hence strength performance suggest that stabilization reactions were relatively permanent. This research performed a strengthening of black cotton soil as subgrade for rural road construction using crushed waste tiles. Different replacement proportions were formed and tested for California Bearing Ratio, Atterberg limit (plastic and liquid), particles size distribution and compaction characteristics. As the compaction curves of black cotton soil reveal, the dry density-water content relationship is comparatively flat at the peak values, and the effect of variation in water content from OMC on dry density is marginal. In addition, while soils show considerable difference between unsoaked and soaked CBR values.