Effect of Asphalt Source on Energy Conservation and Emission Reduction Characteristics of Additive-Based Warm-Mix Asphalt and Life Cycle Assessment in the Construction Phase

As core materials in pavement structures, asphalt mixtures are characterized by intensive energy consumption and significant carbon footprints throughout their construction cycle, making their construction a typical high-carbon process in road engineering. Warm-mix technology, leveraging its key advantages of reducing mixing temperatures and cutting energy consumption and emissions, has emerged as a green alternative to hot-mix mixtures. However, existing studies have lacked systematic environmental impact assessments of combinations of asphalt from different oil sources and warm-mix technologies. This study focuses on the additive type warm-mix technology (Evotherm M1) and uses three typical oil sources of 70# road petroleum asphalt. Using headspace gas chromatography–mass spectrometry (HS–GC–MS) and Life Cycle Assessment (LCA) methods, a systematic analysis was conducted across three dimensions: multi-component pollutant emissions, full life cycle stages, and multi-type warm-mix technologies. The analysis focused on the influence of warm-mix treatment on Volatile Organic Compound (VOC) emissions, as well as energy consumption and carbon emission characteristics throughout the full life cycle of the construction phase. Results indicate that warm-mix treatment significantly inhibits VOC emissions from all three oil source asphalts. The largest reduction was observed in Asp-A (74.66%), followed by Asp-C (69.27%), and the smallest in Asp-B (46.47%). The VOC compositions shifted from being dominated by oxygenates to a coexistence of multi-components such as alkanes and aromatic hydrocarbons. In the life cycle of the construction phase, compared with hot-mix mixtures, warm-mix technology reduced total energy consumption by 5.50%–5.56% and carbon emissions by 4.47%–4.52%. Raw material production and mixture mixing stages were identified as the core links for energy consumption and carbon emissions, accounting for over 80% of the totals. Differences among oil sources mainly stemmed from refinery power structure and the temperature–viscosity properties of asphalt. The research results provide theoretical support for material selection and process optimization of green construction of asphalt pavement using additive-based warm-mix technology.