Stabilization of lateritic soil with eggshell powder

Abstract

In tropical regions, lateritic soil is used in road construction. Therefore, it is accused of being the source of failure of roads due to its high compressibility. There have been many kinds of research on improving the strength of lateritic soil and found many materials to mix with lateritic soil to enhance its strength. Cement and lime were the frequently used stabilizers for lateritic soil, but their environmental impact halted the user's interests. Some eco-friendly materials were also used, but their availability and cost made them less famous. Researchers tried recyclable materials such as eggshell, for they are available as food waste and share the same chemical composition as lime. The effects of eggshell powder on the strength of lateritic soil were remarkable even though they could not replace lime when used at the same concentration. The particle size of eggshell powder that could be convenient for making a good binding and the effect of the protein-membrane present in the eggshell on its stabilizing capacity were not investigated. This research was fundamentally based on laboratory experiments and checked through numerical analysis on-road usage. The aim was on the impact of particle size of the eggshell powder and the effect of protein membrane. The Atterberg limit revealed that the liquid limit fall and the plastic index also fall for different particle sizes, but there were no significant differences within different particle sizes. The particle size affected neither the maximum dry density nor the optimum moisture content. However, the unconfined compression strength was very distinctive for each particle size used. The particle size of eggshell powder less than 150μm and greater than 88μm was the convenient size that could make a good stabilizer with a 3% content concentration at optimum. The protein membrane was found to be reducing the stabilizing ability of the eggshell powder when the content of eggshell powder is less than 4% in soil. The results obtained in the laboratory tests were used in numerical analysis, and the road embankment model testified the improvement of the sub base when stabilized with eggshell powder.