废弃口罩改性沥青流变性能及储存稳定性

Rheological Properties and Storage Stability of Discarded Mask Modified Asphalt

摘要:

为实现废弃口罩的循环利用，分别将2%、4%、6%口罩碎片加入到70#基质沥青中，并研究废弃口罩对沥青使用性能的影响。结果表明：所用口罩为聚丙烯高分子材料，口罩改性沥青主要是物理改性，没有新的官能团产生。随着口罩添加量的增加，沥青的软化点、复数模量、车辙因子增大，针入度及相位角下降，沥青的高温性能得以增强。然而，添加口罩后，沥青的蠕变劲度增大，蠕变速率及蠕变速率劲度比降低，沥青低温抗裂性能劣化。与70#沥青相比，口罩改性沥青的疲劳寿命在2.5%及5%应变水平下至少提升了14.1%、4.3%。改性沥青的相均匀性随口罩添加量增加变差，改性沥青的相分离趋势愈发显著，推荐口罩添加量为4%。

Abstract:

To achieve the recycling of discarded masks, 2%, 4%, and 6% of mask fragments are added to the 70 # matrix asphalt respectively to study the impact of discarded masks on the performance of asphalt. The results show that the mask used is made of polypropylene polymer material, and the mask modified asphalt is mainly physically modified without the generation of new functional groups. With the increase of additive amount of mask, the softening point, modulus of complex number, and rutting factor of asphalt increase, and the penetration and phase angle go down, the high-temperature properties of asphalt are enhanced. However, after the addition of masks, the creep stiffness of asphalt increases, the creep rate and creep rate stiffness ratio reduces, and the low-temperature crack resistance properties of asphalt is degraded. Compared with 70 # asphalt, the fatigue life of mask modified asphalt has increased by at least 14.1% and 4.3% at 2.5% and 5% strain levels. The phase uniformity of modified asphalt is deteriorated with the increase of mask addition amount, and the phase separation trend of modified asphalt is more significant. The recommended additive amount of mask is 4%.