INFLUENCE OF SOIL AND LIME ON THE MECHANICAL AND EROSION PERFORMANCE OF EARTHEN MATERIALS

Abstract

Earthen materials remain widely used in rural construction due to their local availability, low environmental impact, and reduced embodied energy; however, their limited mechanical performance and susceptibility to water erosion restrict broader structural application. This study evaluates the influence of soil mineralogy and lime dosage on the compressive strength, flexural strength, and erosion resistance of stabilized earthen mixtures. Three soils with contrasting mineralogical characteristics were characterized using X-ray fluorescence (XRF) and X-ray diffraction (XRD), and subsequently stabilized with 0%, 3%, 5%, and 8% lime contents. Prismatic specimens were prepared and tested following standardized mechanical and durability procedures. Experimental results were expressed as mean ± standard deviation, while the coefficient of variation (COV) was incorporated to assess data dispersion and material heterogeneity. Mechanical performance was strongly dependent on soil composition, with the T1–T3 mixture stabilized with 3% lime exhibiting the highest compressive strength (0.902 MPa). In contrast, the T1–T2 mixture with 3% lime showed superior erosion resistance, emphasizing the beneficial role of clay-rich fractions in improving durability. Increasing lime content beyond the evaluated range associated with balanced performance did not systematically improve mechanical behavior. The results revealed a clear trade-off between mechanical strength and erosion resistance, indicating that no single formulation simultaneously optimized all properties. Overall, the findings demonstrate that stabilized earthen materials require application-specific optimization based on soil mineralogy, stabilizer dosage, and durability requirements rather than universal formulations.