老化公路SBS改性沥青多次再生的流变性能与耐久性研究

提取随岳高速公路废旧SBS改性沥青作为研究对象,采用0.8粉胶比并叠加9%再生剂配置沥青胶浆,利用旋转薄膜烘烤和PAV叠加仪对SBS改性沥青进行多次老化和再生。然后通过车辙因子G、劲度模数S和蠕变因子m对多次再生SBS改性沥青的流变性能和低温抗疲劳性能进行了回归分析和总结。研究发现:随着老化与再生次数增多,再生剂对于SBS改性沥青的再生效果逐渐变差,粘弹性逐渐降低;高温下多次再生沥青胶浆的车辙因子随着再生次数的增加呈现逐渐增强的趋势,并且三次老化>二次老化>一次老化>三次再生>二次再生>一次再生>原样;中温重复加载试验中二次老化与三次再生的衰减程度差别一般为2%~3%;低温下沥青胶浆的劲度模数与再生次数呈反向关系,多次再生后沥青胶浆的m值不具有明细的规律性,多次再生样品拥有更好抗低温性能,但是m值曲线与原装沥青胶浆的离散型偏大。

Study on Rheological Properties and Durability of SBS Modified Asphalt After Repeated Regeneration

Taking waste SBS modified asphalt from suiyue expressway as the research object,0.8 powder binder ratio and 9%regeneration agent were applied to prepare asphalt mortar.Then the rheological properties and low temperature fatigue resistance of SBS modified asphalt were analyzed and summarized by means of rut factor G,stiffness modulus S and creep factor m.It was found that with the increase of aging and regeneration times,the regeneration effect of regeneration agent on SBS modified asphalt gradually became worse and viscoelasticity gradually decreased.Under high temperature,the rut factor of regenerated asphalt mortar for multiple times gradually increases with the increase of regenerated times,and it aging>for three times,>for two times,>for three times,>for three times,>for two times,and>for one time.The attenuation difference between the second aging and the third regeneration is generally 2%~3%.The stiffness modulus of asphalt mortar has an inverse relationship with the number of regeneration times at low temperature.After repeated regeneration,the m value of asphalt mortar does not have a detailed regularity,and the repeatedly recycled samples have better low-temperature resistance,but the m value curve is relatively large with the discrete type of original asphalt mortar.