Potential valorization of demolition concrete waste in the design of low and medium traffic roads

The construction and the maintenance of road infrastructure consume every year and all over the world a huge amount of natural aggregate, such as crushed stone, gravel, and sand. This dependence on natural aggregates has not only placed tremendous pressure on our environment but has also resulted in severe consequences such as loss of biodiversity, and long-term environmental degradation. As road infrastructure projects expand to accommodate growing populations and urbanization, the extraction and consumption of these natural materials increase exponentially. This creates an urgent need to explore more sustainable and eco-friendly alternatives in order to reduce the environmental footprint of road construction projects. A sustainable solution to reduce the use of naturel aggregate in road pavement is incorporating recycled materials – specifically, recycled construction and demolition waste (RCDW) aggregates – in their construction. These aggregates are derived from dismantled structures and other construction waste. This study aims to evaluate the viability of employing RCDW aggregates in the design of unbound pavement layers. A comprehensive laboratory program was implemented to assess the geometrical, physical, and mechanical properties as well as the bearing capacity of these recycled aggregates. The results indicate that RCDW aggregates exhibit suitable performance characteristics in term of hardness (LA <30 % and MDE <30) and bearing capacity (immediate CBR index >80 %), making them a viable option for use as coarse base and sub-base layers in roads subjected to low to medium traffic volumes. Consequently, these recycled aggregates meet the majority of the specifications required for untreated gravel