Characterization of Viscoelastic Performance and VOC Emission of Warm-Mixed SBS Asphalt Binder Under Different Dosages of Warm-Mixed Additive

Warm-mixed asphalt technology can significantly reduce the heating temperatures required for asphalt pavement construction, which makes it one of the crucial technical approaches in road engineering for achieving energy conservation and emission reduction, and carbon neutrality. Existing research often focuses on designing asphalt materials to ensure optimal service performance, but insufficient attention has been paid to the specific extent of reduction in asphalt fume emissions. However, the latter is a critical factor that cannot be neglected when constructing asphalt pavements in environmentally sensitive regions. Considering the environmental factor, this study systematically explores the comprehensive influence of different warm-mixed additive dosages on the viscoelastic properties and VOC emissions of warm-mixed SBS asphalt binder using rotational viscosity, bending beam rheometer (BBR), dynamic shear rheometer (DSR), and gas chromatography-mass spectrometry (GC-MS) test methods. The findings show that the application of warm-mixed additive does not compromise the comprehensive properties of SBS asphalt binder, but partially enhances its service performance instead. Due to the significant reduction in heating temperature, asphalt VOC emissions are indirectly reduced. Although the warm-mixed additive possesses a certain degree of volatility, its application still shows a significant trend toward emission reduction. Despite 0.4% being a relatively economical dosage of warm-mixed additive, a slight increase to 0.5% can achieve more pronounced environmental benefits in VOC emission reduction while maintaining comprehensive service performance that meets specification requirements. The findings can provide new insights for the application and decision-making of warm-mixed asphalt technology in environmentally sensitive regions.