Long-term performance of pet geogrids with LLDPE coating in alkaline conditions: Exhumation findings post lime and cement stabilization

The increasing demand for sustainable construction practices and cost minimization has spurred interest in using locally available soil for reinforced fill structures. However, cohesive soils on-site often require stabilization treatments to enhance volume stability, strength, compressibility, permeability, and durability. These treatments can induce chemical reactions that dry the soil and alter the clay's surface mineralogy, impacting the pH level. Soils with a pH consistently above 9 is deemed not suitable for conventional PET geogrids due to hydrolysis susceptibility. This research examines the performance of PET geogrids with polyethylene-sheathed tendons in alkaline environments. Through experimental laboratory analyses and exhumation campaigns to assess the real-world conditions and prolonged exposure effects on these geogrids and geostrips, the study presents some considerations on the effects of a specific geogrid structure and coating.