高掺量橡胶沥青的结构与性能

Structure and properties of high-content rubberized asphalt

轮胎胶粉的多重交联网络限制了其在橡胶沥青中的胶粉掺量。用经螺杆反应挤出方法可控再生的再生胶可制备高掺量(质量分数不小于30%)橡胶沥青。通过溶胶含量、门尼黏度和基本性能测试及加工实况观察,并结合红外光谱和光学显微镜微观分析,探讨了胶粉的再生程度及用量对高掺量橡胶沥青结构与性能的影响。结果表明,再生过程中胶粉的化学键发生断裂,部分交联网络被破坏。与传统橡胶沥青相比,高掺量橡胶沥青的分散更均匀,加工流动性和高温储存稳定性均得以改善。提高胶粉的降解再生程度可明显提高其在沥青中的掺量,进一步提高改性沥青的低温柔性和高温抗变形能力,但易出现加工黏度的临界陡增现象。

The content of ground tire rubber was limited by its multiple cross-linking networks.High-content ground tire rubber modified asphalt(mass fraction of ground tire rubber more than 30%)binder could be produced by addition of degraded tire rubbers(DR),which was controllably prepared by reactive screw extrusion using ground tire rubber.The effects of degradation degree and content of DR on structure and properties of DR modified asphalt were analyzed by Soxhlet extraction,Mooney visco-sity,basic physical properties,infrared spectroscopy,and optical microscopic tests.The results showed that chemical bonds broke,and cross-linking network of ground tire rubber collapsed during degradation process.Compared with conventional ground tire rubber modified asphalt binder,DR modified asphalt binder had finer dispersion,lower viscosity and better stability at high temperature.The addition of DR with high degree of degradation increased by a large margin the content of ground tire rubber,leading to further improved deformation ability at low temperature and deformation resistance at high temperature.The steep increased of viscosity at certain rubber content should be noticed.