费托蜡温拌沥青结合料相容性的评定方法

Evaluation Method for Compatibility of Sasobit Warm Mix Asphalt Binder

用溶解度参数计算、离析软化点差值测试、差示扫描量热分析和原子力显微镜微观扫描等方法对比研究了苯乙烯-丁二烯-苯乙烯三嵌段共聚物(SBS)和费托蜡(Sasobit)改性(温拌)剂与70#A基质沥青间的相容性。结果表明,溶解度参数δ不能体现分子量对聚合物相容性的影响,且沥青和某些改性剂均为高分子量的多相结构,共混后的结构复杂,不能简单地将改性沥青当作一个整体。因此,不能使用Hildebrand理论计算公式评价改性剂与基质沥青间的相容性。Sasobit的加入不仅提高了基质沥青的玻璃化转变温度,还明显改变了基质沥青吸热峰曲线的形状,因而与基质沥青良好相容。SBS和Sasobit复合改性剂的加入,大大降低了改性剂与基质沥青间的相容性。

The compatibility between 2 modifiers Styrene-Butadiene-Styrence Block Copolymer （SBS） and Sasobit and 70#A base asphalt was comparatively studied by means of solubility calculation, measurement of difference of segregation softening point, differential scanning calorimetry and atomic force scanning microscope. The results show that the solubility parameter can not reflect the influence of molecular weight on polymer compatibility, due to the asphalt and modifiers all have multiphase structures with high molecular weight, a complex structure should be expected for the bland of the asphalt and a modifier. The compatibility of the modified asphalt can not be simply evaluated as a whole by Hildeb- rand theoretical calculation formula. Adding Sasobit into base asphalt can not only increase the glass transition temperature of the base asphalt, but also change the shape of its endothermic peak curve significantly, so Sasobit has good compatibility with base asphalt. However, adding the two modifiers SBS and Sasobit can greatly reduce the compatibility between modifier and base asphalt.