摘要
【目标】为研究不同活化方式对脱硫胶粉结构及其改性沥青性能的影响机制,采用微波、化学及双螺杆挤出这3种活化工艺对废胶粉进行预处理,并制备相应的胶粉改性沥青。【方法】通过傅里叶红外光谱、扫描电镜和热重分析对活化胶粉的化学组成与微观结构进行表征,同时结合动态剪切流变与低温弯曲蠕变试验评价改性沥青的高低温性能。【结果】微波与化学活化虽能有效断裂胶粉中的不饱和C=C键,但对交联网络结构的破坏有限;双螺杆挤出活化则通过强剪切作用显著破坏多硫交联键,提升胶粉溶解度。流变测试表明,高溶解度胶粉有助于增强沥青的低温抗裂性,但因主链断裂导致高温抗车辙因子下降约30%。此外,双螺杆活化可促进胶粉颗粒细化与表面官能团生成,但过度脱硫会削弱其力学性能。【结论】不同活化工艺通过差异化路径影响胶粉结构与改性沥青性能。微波与化学活化适用于高温性能需求场景,双螺杆挤出活化在提升低温抗裂性上优势显著。研究结果可为胶粉活化工艺的选择及其改性沥青性能的精准调控提供理论依据。
[Objective]The study systematically investigated the influences of different activation methods on the structure of desulphurized rubber powder and the properties of modified asphalt.Three activation processes(i.e.,microwave,chemical,and twin-screw extrusion)were applied to pre-treat the waste rubber powder,and prepare the corresponding modified asphalts.[Method]The chemical composition and microstructure of activated rubber powders were characterized by using Fourier transform infrared spectroscopy,scanning electron microscopy,and thermogravimetric analysis.Simultaneously,the dynamic shear rheometer and bending beam rheometer tests were performed to evaluate the high-and low-temperature performances of modified asphalts.[Result]While the microwave and chemical activations effectively break the unsaturated C=C bonds in the rubber powder,they have limited effects on the destruction of crosslinked network structure.In contrast,the twin-screw extrusion activation significantly disrupts the polysulfide crosslinks through shear forces,enhancing the solubility of rubber powder.The rheological tests reveal that the rubber powder with high solubility improves the low-temperature cracking resistance of asphalt,but the main chain fracture leads to 30%decrease in high-temperature rutting resistance.Moreover,the twin-screw extrusion activation promotes the refinement of rubber powder particles and the generation of surface functional groups,but the excessive desulphurization weakens its mechanical properties.[Conclusion]Different activation processes affect rubber powder structure and modified asphalt performance through distinct pathways.The microwave and chemical activation are suitable for scenarios requiring high-temperature performance,while the twin-screw extrusion activation has significant advantages in improving low-temperature crack resistance.These findings provide the theoretical guidance for selecting activation processes and precisely controlling the performance of rubber powder modified asphalt.
作者
王菊山
范永强
王学娟
张绍聪
WANG Jushan;FAN Yongqiang;WANG Xuejuan;ZHANG Shaocong(Zhangye Highway Development Center of Gansu Province,Zhangye,Gansu 734000,China;Gansu Changlong Highway Maintenance Technology Research Institute Co.,Ltd.,Lanzhou,Gansu 730030,China)
出处
《公路交通科技》
北大核心
2025年第8期43-52,共10页
Journal of Highway and Transportation Research and Development
关键词
道路工程
脱硫胶粉活化
活化工艺
改性沥青
流变性能
微观机制
road engineering
desulphurized rubber powder activation
activation process
modified asphalt
rheological property
microscopic mechanism
