Evaluation of the Environmental and Economic Impacts of Warm-Mix Asphalt Using Life-Cycle Assessment

The use of warm-mix asphalt (WMA) has received considerable attention in recent years to reduce energy consumption and air emissions. Despite these promising benefits, the promotion of WMA based on a single factor such as reduced energy consumption or reduced emissions does not provide a complete evaluation of this technology and may omit critical environmental factors that should be considered in the decision-making process. The objective of this paper was to conduct a life-cycle assessment of WMA technology as compared with a conventional hot-mix asphalt mixture. To achieve this objective, a life-cycle inventory (LCI) that quantifies the energy, material inputs, and emission during aggregate extraction, asphalt binder production, and hot-mix asphalt production and placement, was developed. Based on this inventory, life-cycle impact assessment of WMA technology was conducted. Based on this analysis, it was determined that WMA provides a reduction of 24% on the air pollution impact of hot-mix asphalt (HMA) and a reduction of 18% on fossil fuel consumption. Overall, the use of WMA is estimated to provide a reduction of 15% on the environment impacts of HMA.