Multi-dimensional laboratory characterization: VOCs emission and evolution in warm-mix synchronous rejuvenated (WMA-SR) asphalt pavement throughout construction stages.

While Warm Mix Asphalt-Synchronous Rejuvenation (WMA-SR) technology exhibits significant energy-saving and emission-reduction potential, its dynamic emission behaviors and the environmental and health risks introduced by chemical additives remain unexplored. This study transitions the evaluation paradigm from a conventional mass-based approach to a multi-dimensional assessment framework. Using a laboratory-controlled system and TD-GC-MS, the evolution of volatile organic compounds (VOCs) across three critical construction stages (asphalt storage tank, mixing plant, and paving site) was systematically characterized. Results indicate that WMA-SR acts as an intrinsic source-control strategy, reducing VOC emissions compared to conventional HMA across all stages. Furthermore, its emission profile naturally attenuates from a complex matrix in the storage tank to a simplified composition at the paving site, governed by aggregate adsorption and sequential temperature drops. This simplification significantly minimizes co-elution interference, yielding better identification reliability. Crucially, the multi-dimensional assessment reveals dynamic risks. Regarding environmental impact, the dominant precursors shift dynamically: while different chemical components govern the storage tank phase, the Ozone and Secondary Organic Aerosol Formation Potentials (OFP and SOAFP) are distinctly dominated by OVOCs and alkanes, respectively, during the paving stage. Health risk assessment highlights that while overall toxicity experiences a drastic temperature-driven decline, acute non-carcinogenic risks from 2-propenal (HI > 60) in the storage phase and persistent benzene exposure across all stages demand targeted intervention. This study rigorously quantifies the full-cycle WMA-SR emissions, providing a robust theoretical foundation for sustainable pavement engineering.