纳米SiO₂/橡胶粉复合改性沥青性能研究

Study on the Performance of Nano-SiO₂/Rubber Powder Composite Modified Asphalt

摘要: 为增强重交沥青路面寿命，确保其在服役周期内保持良好的高低温性能，向基质沥青中添加纳米SiO₂和橡胶粉两种外掺剂。首先，基于针入度试验、延度试验、软化点试验分析改性沥青的基本性能；其次，通过动态剪切流变试验(DSR)，评价不同温度和不同频率等因素对复合改性沥青高温性能的影响；最后，应用弯曲梁流变试验(BBR)，分析纳米SiO₂/橡胶粉复合改性沥青的低温流变性能；研究结果表明：纳米SiO₂的加入，使得橡胶粉改性沥青的针入度降低，软化点、延度升高；同时，橡胶粉改性沥青的车辙因子有所提高，可知纳米SiO₂提高了橡胶粉改性沥青的高温抗车辙性能；劲度模量S值降低、蠕变速率m值升高可以发现，纳米SiO₂和橡胶粉复合掺加后提高了沥青的低温抗裂性能。

Abstract: To enhance the lifespan of heavy-duty asphalt pavements and ensure good performance under both high and low temperatures throughout their service life, Nano-SiO₂ and rubber powder were added as external additives to the base asphalt. First, the basic properties of the modified asphalt were analyzed through penetration tests, ductility tests, and softening point tests. Next, the high-temperature performance of the composite modified asphalt was evaluated using Dynamic Shear Rheometer (DSR) tests, considering various temperatures and frequencies. Finally, the low-temperature rheological properties of the Nano-SiO₂/rubber powder composite modified asphalt were analyzed using the Bending Beam Rheometer (BBR) test. The results indicate that the addition of Nano-SiO₂ reduces the penetration index and increases the softening point and ductility of the rubber powder modified asphalt. Additionally, the rutting factor of the rubber powder modified asphalt improved, suggesting that Nano-SiO₂ enhances the high-temperature rutting resistance of the rubber powder modified asphalt. The reduction in stiffness modulus (S value) and the increase in creep rate (m value) demonstrate that the combined addition of Nano-SiO₂ and rubber powder improves the low-temperature crack resistance of the asphalt.