Cost–benefit analysis of recycled materials in road asphalt layer: a case study in Egypt

Purpose The purpose of this research is to evaluate the feasibility of incorporating recycled construction and demolition waste (CDW) materials, specifically Reclaimed Asphalt Pavement (RAP), into asphalt layers for road construction in Egypt. It aims to compare the economic and environmental impacts of using raw materials versus partially replacing them with recycled materials. Design/methodology/approach The study follows Egyptian code requirements to assess the viability of using recycled CDW in asphalt road construction. It compares two scenarios: exclusive use of raw materials versus partial replacement with recycled RAP. A new decision-support tool, Cost Impact of using Recycled Materials in Roads (CIRMR), was developed using visual basic application and validated through a real-road case study in Egypt, which involved replacing 50% of raw materials with RAP. Findings The case study demonstrated a 70.1% economic cost reduction, primarily from the value gained by reducing landfill area usage. Environmental impact improved by 230.3%, mainly due to lower carbon emissions. The partial use of RAP and recycled bitumen met quality standards, highlighting the feasibility of sustainable materials in road construction. Originality/value This research addresses a gap in the application of recycled materials in road construction in Egypt. The CIRMR tool offers an innovative decision-making approach, validated through practical case studies, and promotes sustainable construction practices. The findings provide a framework applicable to similar contexts globally.