Carbon footprint of block prepared with recycled aggregate: a case study in China

Abstract

This study aims to evaluate the carbon footprint of concrete blocks prepared with local recycled waste materials derived from Changsha using life cycle assessment (LCA) technique. The local life cycle inventory was developed for conducting case-specific assessment of concrete blocks prepared with recycled aggregates (RA) sourced from a local construction and demolition (C&D) waste. The result is also compared with concrete blocks made by natural aggregates (NA). The results show that greenhouse gases (GHGs) emissions related to the production of RA were 3 kg CO2 eq., which is 57% lower than the production of NA. However, the adoption of RA in concrete blocks production induced higher GHGs emissions than NA concrete blocks due to higher amount of cement was needed to achieve a same required mechanical strength. Guidelines to further design and develop sustainable green concrete blocks prepared with RA to meet the mechanical requirements based on the current situation in Changsha city has also been highlighted.