Cross-country life cycle assessment of construction and demolition waste recycling with evaluation of energy use, carbon emissions, and regional trade-offs

Recycling construction and demolition waste (C&DW) into recycled concrete aggregates (RCA) is a sustainable strategy to reduce resource consumption and emissions. Most life cycle assessments (LCAs) focus on a single country and region, limiting broader applicability. This study conducts a novel comparative LCA of C&DW recycling systems across six countries and regions. By evaluating energy consumption, global warming potential (GWP), and fossil CO₂ emissions in recycled concrete aggregate (RCA) production, significant regional differences are revealed, largely influenced by infrastructure, processing efficiency, and transport. In countries with mature recycling systems, RCA production reduces GWP by up to 97% per ton compared to natural aggregates manufacturing. Conversely, longer transport distances or inefficient operations in less developed systems can offset these benefits. While RCA generally demonstrates lower environmental impacts, its advantage is highly context-dependent. However, standardized global guidelines remain challenging due to regional disparities in waste sources and processing.