Research on Direct Energy Consumption and Carbon Emission of Asphalt Pavement Maintenance Engineering

The Chinese ‘double carbon’ target should be actively promoted by highway infrastructure while facilitating rapid economic development. However, there is currently no clear evaluation standard for energy consumption and carbon emissions during the maintenance of millions of kilometers of roads. This study divided asphalt pavement maintenance projects into four stages: raw material production, asphalt mixture production, paving and rolling, and materials transportation. The analytic hierarchy process (AHP) was applied to analyze the energy consumption and carbon emission weights of various stages in several typical maintenance projects. Two evaluation indexes and calculation methods, energy consumption index (ECI) and energy consumption cost index (ECCI), were proposed to quantitatively analyze the direct energy consumption and carbon emission of maintenance projects. The research showed that the production of raw materials and materials heating before mixing had the highest energy consumption, with the ECI index values of these two stages accounting for more than 80% of the overall ECI index value. The upper layer and overlay layer in the maintenance project required more energy and carbon emissions for better performance. The ECI value of maintenance technology using modified asphalt was 100% higher than that of matrix asphalt. The energy-saving effect of low temperature or regenerative maintenance technology was significant, with the ECCI index of cold in-place recycling being more than 50% lower than that of conventional maintenance projects. © 2024 Cailiao Daobaoshe/ Materials Review. All rights reserved.