Influence of Compactive Efforts and Bagasse Ash on Lime Modified Laterite

Abstract

The effect of three compactive efforts (British Standard Light, BSL, West African Standard, WAS and British Standard Heavy, BSH) and bagasse ash (an agro-industrial waste from sugar mills) admixture on lime modified laterite are presented. The laterite, classified as A-7-6 using AASHTO soil classification, collected from Shika area of Zaria, was modified with a maximum of 4 % lime and 8 % bagasse ash, by dry weight of the soil. Test results showed increase particle sizes with higher dosages of the additives; the particle sizes decrease with higher compaction energy. There was decrease in maximum dry density (MDD) with higher dosages of the additives and compaction energy. Optimum moisture content (OMC) increased with higher concentrations of additives but decreased with higher compactive effort. There was also improvement in the shear strength parameters with higher dosages of additives and compaction energy. The results show that the soil modified with an optimum of 1% lime and 6% bagasse ash admixture meets the Highway Research Board limits, Millard and O’Relly freeflow criterion as well as the limits set by Nigerian General Specifications, at all the compaction energy levels considered.