Quantitative assessments of GHG and VOCs emissions of asphalt pavement contained steel slag

Abstract

Using steel slag aggregate in asphalt pavement is recognized as novel alternative to enhance the environmental benefits, however, lacking quantitative analysis on its air components emissions largely hinders the fulfilment of sustainable road development. The study conducted the comparative research for the steel slag and the natural aggregate asphalt pavement from asphalt volatile organic compounds (VOCs) and greenhouse gas (GHG) emissions. The self-assembled gas generator and gas chromatography-mass spectrometer (GC–MS) were used to study the characteristics of asphalt VOCs. Moreover, the GHG emissions of asphalt pavement life cycle have been quantified with a prospective life cycle assessment (LCA). Different from traditional cognition, the research results showed that using steel slag aggregate in asphalt mixture would cause more asphalt VOCs and GHG emissions than natural aggregate in the life cycle of asphalt pavement. Specifically, comparing to the natural aggregate, the asphalt pavement contained steel slag aggregate generated extra 2 % to 30 % concentrations for primary VOCs components, and 11.86 t equivalent CO2 in the 20-year life cycle of asphalt pavement. The study provides valued reference for air pollution controlling and low-carbon development of asphalt pavement.