Study of the Strength and Microstructure of Cohesive Soil Using Treated Agave Americana fiber and Lime as Stabilizing Additives

Arias Fernández K.Y.; Garcia Chumacero J.M. · International Journal of Pavement Research and Technology (2026) · DOI: 10.1007/s42947-026-00906-3

Resumen

Cohesive soils with low bearing capacity represent a common limitation in infrastructure projects due to their high plasticity and variable behavior in response to changes in moisture content. The objective of this study was to evaluate the effect of incorporating Agave americana fiber (AF) and hydrated lime on improving the mechanical properties and microstructure of a cohesive clay soil with low plasticity (CL). An experimental process was carried out that included the selection of soil obtained at a depth of 1.50 m. The plant fiber was subjected to cleaning, immersion, alkaline treatment with 5% NaOH, drying, and cutting into 30 mm lengths before being incorporated into the soil. The dosages used were 1.0%, 1.5%, and 2.0% fiber, and 4%, 6%, and 8% lime, which were added by weight to the dry soil. The mixtures were evaluated using Modified Proctor and California Bearing Ratio (CBR) tests, supplemented with X-ray Diffraction (XRD) and Scanning Electron Microscopy coupled with Energy-Dispersive X-ray Spectroscopy (SEM-EDS) microstructural analyses, and statistical analysis using Analysis of Variance (ANOVA). The results showed that the fiber slightly reduced the maximum dry density but increased the CBR by improving stress transfer and controlling deformation. On the other hand, lime increased soil compaction and strength through chemical reactions that reduce plasticity. The most notable finding was that the optimal combination of 2.0% AF:8% Lime achieved the highest values of maximum density (1.806 g/cm³) and CBR (12.65% at 95% compaction and 13.80% at 100%), tripling the strength of the natural soil. These results are statistically significant (p < 0.05) and demonstrate that the fiber-lime mixture is an effective, economical, and sustainable alternative for stabilizing cohesive soils with low bearing capacity. © Chinese Society of Pavement Engineering 2026.

Instituciones: Universidad Señor de Sipán