Clay soils with low bearing capacity pose a common challenge for road construction and other infrastructure projects. This study evaluated the reuse of inert mine tailings as stabilizing materials, both through their direct incorporation into the soil and as part of a mortar made from tailings and cement. Dosages of 5, 10, 15, and 20 percent were analyzed, and the results were compared with natural soil and with a mixture stabilized with 15 percent cement. The mortar used completely replaced conventional fine aggregate with mine tailings.
The mixtures were characterized through physical and mechanical tests that assessed their plasticity, compactability, bearing capacity, and strength. Among the mix proportions studied, the mixture with 15% tailings-cement mortar exhibited the most balanced performance, increasing the soil’s CBR from 5.1% to 15.4%, achieving an unconfined compressive strength of 5.76 kg/cm², equivalent to an 82% increase compared to the natural soil, and yielding a plasticity index of 9%. Taken together, these results demonstrate a significant improvement in the bearing capacity and mechanical behavior of the clay soil, with performance comparable to that of the mixture stabilized with 15% cement.
These findings provide a technical basis for guiding future research and optimizing the dosages of tailings and tailings-cement mortar in the stabilization of clay soils with low bearing capacity. Furthermore, they demonstrate the potential for repurposing mining tailings as a resource for geotechnical applications, promoting more responsible management of this waste, the circular economy, and the development of sustainable solutions for improving road subgrades.
Researchers FICT - ESPOL
Aurelia Magaly Gaibor Lombeida, M.Sc.
Luis Jordan Aguilar Salas, M.Sc.
Daniel Andrés Falquez Torres, M.Sc.
Davide Besenzon, Ph.D.
Samantha Tamara Jiménez Oyola, Ph.D.
Partner Institutions:
Aurelia Magaly Gaibor Lombeida, M.Sc.
Pontifical Catholic University of Ecuador
Sandri Castro Angulo, M.Sc.
Pontifical Catholic University of Ecuador
Autonomous University of Nuevo León
Sustainable Development Goals (SDGs)
SDG 9: Industry, Innovation, and Infrastructure
SDG 12: Responsible Consumption and Production
