Laboratory Assessment for Utilizing Eggshell Waste on Iowa Soil Stabilization

Iowa has become the number one state in America in egg production in the past several years. Consequently, large amounts of eggshells are generated as unused wastes. Eggshell is made almost entirely of calcium carbonate crystals. Due to the rich calcium in eggshells, it has the great potential to be used as a calcium-based stabilizer material. However, such benefits of eggshells have not been evaluated and practiced in Iowa yet. This study aims to assess the beneficial use of Iowa eggshells as bio-based cementitious materials in stabilizing Iowa subgrade soils. Eggshells were ground into eggshell powder (ESP) through a coffee grinder. The testing results indicated that ESP treatment could elevate the plasticity of soil as well as the strength. The optimum content of ESP is 8%, which can achieve up to 30% strength improvement. The outcomes of this study indicate that ESP could be used as a non-traditional additive for Iowa soil stabilization.