Life Cycle Assessment of Asphalt Concrete Construction Stage and Impacts of Construction Equipment Idling

The National Asphalt Pavement Association (NAPA) has developed an Environmental Product Declaration (EPD) program that effectively measures the cradle-to-gate life cycle stages of asphalt pavement. However, there is limited information available regarding the construction stage of asphalt pavement in life cycle assessment (LCA). This paper aims to address this gap by quantifying the environmental impacts of the construction stage (A4 and A5) of asphalt pavement for 11 test sections. These sections include eight from the 2022 MnROAD experiment, which featured asphalt mixtures with recycled rubbers, recycled plastics, and synthetic fibers, and three from the Federal Highway Administration (FHWA) Climate Challenge project on US-82 in Alabama, which used asphalt mixtures containing synthetic fibers and warm mix additives. LCA of the construction stage of the 11 test sections was conducted by combining foreground data collected during construction with life cycle inventories for off-road equipment from the Environmental Protection Agency (EPA). Furthermore, data on the idling of construction equipment due to mix delivery delays were gathered and analyzed to determine the effects of these delays on emissions. Initial findings indicate that eliminating the idling of construction equipment by maintaining a balance between production, trucking, and paving could lower greenhouse gas emissions by 8% to 21%.