【摘要】 针对DOA-SBS复合改性沥青改性机理复杂、改性结果变异性较大、难以形成统一生产工艺的问题，借助多尺度分析方法，以揭示DOA与SBS复合改性机理，为提升DOA的利用率提供技术依据。基于正交试验设计了9种不同SBS与DOA掺量的复合改性沥青样品，系统分析了它们的基本性能、流变性能、抗老化性能变化规律，并从化学层面揭示了其复合改性机理。结果表明：SBS掺量是影响复合改性沥青高温性能的关键，DOA可调节沥青稠度，但过量掺入会显著劣化低温延度；增延剂的引入可有效改善低温性能，并与DOA表现出协同增强效应。DOA中的芳香分可促进SBS溶胀分散，其重质组分则参与构建稳定的胶体结构，但DOA过量会打破体系组分平衡；抗老化性能取决于SBS与DOA协同形成的结构稳定性，SBS不足导致聚合物结构松散，DOA过量则引发SBS过度溶胀，从而更易遭受老化损伤；当SBS质量分数为4.0%、DOA质量分数为15%,并辅以1%增延剂和1%橡胶油时，二者协同效应最优，使复合改性沥青在宽温域内兼具优异的高温流变性能、抗老化能力及良好的低温性能。DOA-SBS复合改性沥青的性能表现取决于二者的协同作用程度，在最佳配比下可实现复合改性沥青高低温性能的平衡优化。更多还原

【Abstract】 To address the challenges posed by the complex modification mechanism of DOA-SBS composite modified asphalt, the significant variability in modification outcomes, and the difficulty in establishing a unified production process, this study aims to employ multi-scale analytical methods to elucidate the composite modification mechanism of DOA and SBS, thereby providing a technical basis for enhancing DOA utilization. In this study, nine types of composite modified asphalt samples with varying SBS and DOA contents were designed based on an orthogonal experimental approach. Their fundamental properties, rheological characteristics, and aging resistance were systematically analyzed, and the composite modification mechanism was elucidated from a chemical perspective. The results indicate that SBS content is a key factor influencing the high-temperature performance of the composite modified asphalt. DOA can adjust asphalt consistency. However, excessive DOA content significantly deteriorates low-temperature ductility. The introduction of an extensibility modifier effectively enhances low-temperature performance and exhibits a synergistic enhancement effect with DOA. The aromatic components in DOA promote the swelling and dispersion of SBS, while its heavy components contribute to the formation of a stable colloidal structure. However, excessive DOA disrupts the compositional balance of the system. Aging resistance depends on the structural stability formed by the synergy between SBS and DOA. Insufficient SBS leads to a loose polymer structure, while excessive DOA induces over-swelling of SBS, rendering the material more susceptible to aging damage. When the SBS content is 4.0%, DOA content is 15%, supplemented with 1% extensibility modifier and 1% rubber oil, the synergistic effect between the two is optimized, resulting in a composite modified asphalt that exhibits excellent high-temperature rheological properties, aging resistance, and favorable low-temperature performance across a wide temperature range. The performance of DOA-SBS composite modified asphalt depends on the degree of synergy between the two components. With the optimal formulation, a balanced optimization of both high-and low-temperature performance can be achieved.更多还原