Long-Term Tensile Behavior of a High-Strength Geotextile after Exposure to Recycled Construction and Demolition Materials

Abstract

The use of recycled construction and demolition (C&D) materials as an alternative backfill in the construction of geosynthetic-reinforced structures, such as embankments and retaining walls, has been pointed out as a sustainable and effective means of attenuating the environmental impacts associated with C&D waste disposal to landfill, while also reducing natural resource depletion. Creep is an important time-dependent mechanical property that must be considered when geosynthetics are used in reinforcement applications. In this study, a series of creep rupture tests was carried out to characterize the long-term tensile response of a high-strength geotextile typically used for soil reinforcement. To assess the potential chemical and environmental degradation induced by recycled C&D aggregates on the long-term response of this geosynthetic, the creep strain and rupture behavior of fresh specimens was compared with that of specimens that were previously exposed to recycled C&D materials and a natural soil (used as a reference) for a period of 24 months, under real environmental conditions. Test results have shown that the short-term tensile strength properties of this geotextile can be considerably reduced after exposure to the backfill materials. Conversely, for long-term conditions, the exhumed specimens led to higher estimates of the retained strength at the design lifetime, implying that the use of fresh specimens for creep rupture testing is a conservative (i.e., safe) procedure with regard to the analysis of the long-term strength of this geosynthetic. Similar effects were induced by the exposure of the geotextile to the recycled C&D material and the natural soil, which supports the feasibility of using recycled C&D aggregates as a sustainable replacement to conventional backfill materials of geosynthetic-reinforced structures.