Stabilization of Makurdi Shale Using Bagasse Ash

The growing cost of traditional stabilizing agents and the need for the economical utilization of industrial and agricultural wastes for beneficial engineering purposes has prompted an investigation into the stabilizing potential of bagasse ash in highly expansive shale soil. This research work is aimed to evaluate the suitability of bagasse ash for stabilization of expansive shale soil. The laboratory work involved index properties to classify the soil sample. The preliminary investigation of the soil shows that it belongs to A-7-6 class of soil in the AASHTO soil classification system. Soils under this class are generally of poor engineering use. Atterberg limits, compaction and CBR tests were used to evaluate properties of stabilized soil. The soil was stabilized with bagasse ash in stepped concentration of 0 %, 2%, 4 %, 6 %, 8 % and 10 % by dry weight of the soil. Analysis of the results shows that slight improvement on the geotechnical properties of bagasse ash stabilized soil. Bagasse ash reduces plasticity index, maximum dry density with an increase in optimum moisture content and CBR with all higher bagasse ash contents. From this study, improvements observed in the strength properties of bagasseh ash treated shale were below the minimum values specified for road building materials. Hence, it is recommended for use as a modifier, in the stabilization of shale with either cement, lime or other additives for road work.