INDEX AND COMPACTION CHARACTERISTICS OF LATERITIC SOIL TREATED WITH AN OPTIMAL CONTENT OF RICE HUSK ASH MIXED WITH QUARRY DUST AND CEMENT.

Abstract

The effect of cement and quarry dust (QD) on the index and compaction properties of lateritic soil treated with 10% Rice husk ash (RHA) obtained from Offa Kwara State Nigeria was studied. The index properties of the soil and that of the soil treated with 10% RHA mixed with cement and quarry dust in the proportions of 2%, 4%, 6%, 8% and 10%, 20%, 30%, 40% respectively were determined. Subsequently, specimens of soil samples treated with 10%RHA were prepared and compacted using the British standard light energy level by combining cement in proportions of 0%, 2%, 4%, 6%, and 8% mixed with quarry dust in proportion of 0%, 10%, 20%, 30%, 40%. From the results obtained, the sample was classified as sandy clay (SC) according to the Unified soil classification system (USCS) and A-6 according to the AASHTO classification system. The Plastic and liquid limits of the treated sample increased with the addition of cement but decreased as the QD content was increased. The specific gravity increased on the addition of cement and QD but started decreasing when the cement content exceeded 4%. The maximum dry density increased throughout the experiment in the presence of the stabilisers used and it attained a peak value of 1915 Kg/m3 from an initial value of 1780Kg/m3. The results obtained from this experiment recommends an optimal mix proportions of 40%QD + 10%RHA + 4% Cement and 20%QD + 10%RHA + 6% cement when using the admixtures on an A-6 lateritic soil for construction purposes.