Liu Xiaoyan, Li Ping, Pan Jingsheng
Department of Civil Engineering, Chengdu Technological University, Yibin, China.
PLoS One. 2025 Jun 16;20(6):e0325103. doi: 10.1371/journal.pone.0325103. eCollection 2025.
This study focused on the aging issues of asphalt pavement in high-temperature and high-humidity climatic zones, using SBS-modified asphalt with different additive contents as research objects to systematically investigate the aging evolution mechanisms under coupled hygrothermal conditions. A dual-temperature control system (60°C and 70°C) was constructed to conduct thermal-oxidative aging and wet-dry cycle aging tests. Multidimensional indicators including penetration ratio, softening point ratio, and ductility ratio were utilized to characterize the time-dependent aging characteristics of materials. Additionally, dynamic shear rheology (DSR) tests and rutting tests were integrated to comprehensively evaluate the high-temperature performance degradation of asphalt and its mixtures with varying modifier contents under cyclic aging. The research aimed to reveal the hygrothermal-coupled aging mechanisms and provide theoretical foundations for durable pavement design in humid tropical regions. Experimental results demonstrated that after thermal-oxidative and wet-dry cycle aging at 60°C and 70°C, the performance indices of SBS-modified asphalt with different additive contents deteriorated significantly. Specifically, the penetration ratio decreased by an average of 29.1%, the ductility ratio declined by 14.6%, and the softening point ratio increased by 60.3%. Concurrently, high-temperature rheological performance exhibited progressive degradation. Notably, increased SBS modifier content was observed to mitigate the aging-induced performance attenuation of modified asphalt. Analytical findings suggested that while higher SBS content enhanced structural stability to some extent, the presence of elevated temperature and moisture accelerated the degradation of SBS modifiers and the aging of base asphalt, thereby exacerbating the overall aging of modified asphalt and leading to performance deterioration.
本研究聚焦于高温高湿气候区沥青路面的老化问题，以不同添加剂含量的SBS改性沥青为研究对象，系统地研究了湿热耦合条件下的老化演变机制。构建了双温度控制系统（60°C和70°C）来进行热氧化老化和干湿循环老化试验。利用针入度比、软化点比和延度比等多维指标来表征材料随时间变化的老化特性。此外，结合动态剪切流变（DSR）试验和车辙试验，全面评估了不同改性剂含量的沥青及其混合料在循环老化下的高温性能退化情况。该研究旨在揭示湿热耦合老化机制，为潮湿热带地区耐久性路面设计提供理论基础。实验结果表明，在60°C和70°C下进行热氧化和干湿循环老化后，不同添加剂含量的SBS改性沥青的性能指标显著恶化。具体而言，针入度比平均下降29.1%，延度比下降14.6%，软化点比提高60.3%。同时，高温流变性能呈现出逐渐退化的趋势。值得注意的是，观察到增加SBS改性剂含量可减轻改性沥青老化引起的性能衰减。分析结果表明，虽然较高的SBS含量在一定程度上增强了结构稳定性，但高温和水分的存在加速了SBS改性剂的降解和基质沥青的老化，从而加剧了改性沥青的整体老化并导致性能劣化。
