Integrating recycled materials in road construction: A cost-effective and sustainable approach

The construction industry's accelerated growth has intensified the generation of construction and demolition waste (CDW), raising critical environmental and economic concerns. This study addresses the pressing need for sustainable CDW management by evaluating the feasibility of integrating recycled materials into road asphalt layers. A comparative assessment was conducted between conventional road construction methods using raw materials and an alternative approach employing partial substitution. To support stakeholder decision-making, a novel modelling tool, CIRMR (cost impact of recycled materials in roads), was developed using Visual Basic for Applications. The model quantifies both economic and environmental impacts, incorporating factors such as material costs, transportation, landfill value recovery and CO2 emissions. The tool was validated through an applied case study in Egypt, confirming its practical utility. Findings reveal that incorporating recycled materials can lead to substantial cost reductions in asphalt construction and deliver marked environmental improvements, primarily through reduced landfill dependency and lower carbon emissions. The study also underscores the influence of key parameters—such as transportation distance and replacement ratios. The outcomes advocate for mainstreaming recycled materials in road infrastructure as a cost-effective and environmentally responsible strategy, offering a replicable framework for sustainable construction practices.