Climate change mitigation investigating asphalt pavement solutions made up of plastomeric compounds

Abstract

Aiming to mitigate climate change effects associated with the construction of asphalt pavements, two different polymers, namely a plastomeric compound (PC) and a graphene-enhanced recycled (hard) plastic compound (GRPC), were introduced into hot mix asphalt (HMA) for binder layers of road pavements. The study revolved around the investigation of the mechanical performance and life cycle environmental impacts of four HMAs: a) HMA with neat bitumen and cold-added PC (HMAPC), b) HMA with neat bitumen and cold-added GRPC (HMAGRPC), c) HMA containing neat bitumen (HMANB) and d) HMA made up of modified bitumen with 5% Styrene Butadiene Styrene (HMAPMB). The mechanical characterization results showed that HMAPC and HMAGRPC increased their crack propagation resistance compared to HMANB, respectively by 35 and 39%, while HMAPMB exhibited the lowest rut depth since it is specifically designed to keep the deformation low at high temperature. The rational design of pavement superstructures was carried out by using in turn each designed asphalt mixture for the binder layer; the HMAGRPC resulted in 12 years-longer service life compared to that of a traditional HMA. The application of life cycle assessment methodology highlighted that the solution made up of GRPC resulted in significantly reduced environmental impact indicators; in detail, the greatest reduction was achieved for the marine ecotoxicity (−58% and −22% compared to those with HMANB and HMAPMB in the binder layer, respectively) for the overall lower amount of fuels used and lower NOx emissions (−3 kg) during transportation phases and supply of raw materials.