Valorization of Fine-Grain Construction and Demolition (C&D) Waste in Geosynthetic Reinforced Structures

Abstract

Current environmental awareness compels all citizens to reduce the production of waste and use recycled materials. Recycled materials coming from construction and demolition (C&D) waste are progressively being used in civil engineering applications, such as base and sub-base layers of transport infrastructures and concrete production. However the fine grain fraction of C&D recycled materials is not considered appropriate for those applications, being frequently landfilled instead of reused. This paper assesses the possibility of using fine grain C&D recycled materials as backfilling of geosynthetic reinforced structures (embankments and retaining walls), replacing the soils typically used in the construction of these structures. The study has involved physical, mechanical and environmental characterization of C&D recycled materials, characterization of the interfaces between the fill material and three geosynthetics, through direct shear and pullout tests, and the evaluation of the potential damages induced by the C&D recycled materials on the short-term tensile behaviour of the geosynthetics. The results presented in this paper support the suitability of using C&D recycled materials in the construction of geosynthetic reinforced structures and thus diminishing our carbon footprint, through the reduction of the environmental impacts induced by C&D waste landfilling and by the extraction of natural aggregates.