Effect of Locust Bean Pod Ash on Compaction Characteristics of Weak Sub Grade Soils

Abstract

Chemical stabilization of weak sub grade soils using Locust Bean Pod Ash (LBPA) was studied with respect to compaction characteristics and appropriate recycle of Waste Agricultural Biomass (WAB). The soils used in this study were obtained from old borrow pits along Minna-Kataeregi-Bida road in northern Nigeria and analyzed for their main index properties and compaction. The experimental results revealed that Locust Bean Pod Ash reduces the maximum dry density from 1.68-1.62, 1.33-1.304 and 1.62-1.50 respectively for the various soil samples while it increases the optimum moisture content from 10.4-11.5 %, 18.0-19.5% and 12.03-18.50 % respectively thus, improving the compaction properties. Considering compaction characteristics and economy, 6-10 % weight of stabilizer to the soils was considered the required optimum values for satisfactory accomplishment of the stabilization of the weak soil as road sub base. The conversion of the WAB to a pozzolanic material for soil stabilization provided at least three significantly desirable components in modern day total quality development of highways; environmental pollution control, recycling of waste for new useful material and rejuvenation of an exhausted source of construction materials (borrow pits).