Life cycle and performance assessment of recycled aggregates in pavement construction: a cross-sectoral, open-loop approach

Increasing environmental challenges in pavement engineering, have shifted focus toward sustainable and circular alternatives to conventional unbound road subbases. The use of Construction & Demolition Wastes (C&DW) could enhance the realisation of sustainability and circular economy and reduce landfill wastes and their environmental implications. Thus, the aim is to develop and utilise a framework to quantify the environmental impacts of subbase production with C&DW. Utilising predominantly primary data an LCA was performed for a conventional and two alternative types of subbases: one with recycled aggregates from C&DW and one with Reclaimed Asphalt (RA). Results place the RA subbase first, followed by the more impactful subbases: C&DW and conventional. The most impactful stage for all alternatives is the raw material acquisition and the sensitivity analysis indicates that the optimisation of the regional/national end-of-waste management in terms of geographical coverage and transport distances can beneficially affect the overall environmental impacts.