Comparative Life Cycle Assessment of End-of-Life Scenarios of Carbon-Reinforced Concrete: A Case Study

Abstract

This study assesses the environmental performance in the end-of-life (EoL) of double walls made of carbon-reinforced concrete (CRC) and steel-reinforced concrete (SRC). The most feasible CRC EoL scenarios are evaluated using life cycle assessment and their environmental performances are then compared to those of SRC. The results showed that mechanical recycling is the best CRC EoL scenario, with a global warming potential (GWP) of 7.0 kg CO2 eq., while the use of renewable energy can save over 50% of GWP. For SRC, the best scenario was obtained using a mobile recycling plant (GWP of 8.8 kg CO2 eq.). In general, the further life of the reinforcements is hardly comparable. Steel can be recycled nearly without losses or downcycling, while a closed cycle of carbon fibers is not yet possible. Therefore, carbon fiber properties or EoL processes need to be improved for a closed loop with an optimized environmental performance.

Keywords

• LCA
• end of life
• recycling
• carbon-reinforced concrete
• steel-reinforced concrete
• circular economy