Low temperature performance of HMA using vacuum tower distillation bottoms modified with bio-derived rejuvenators according to the SCB test

Vacuum tower distillation bottoms (VTB) – a stiff form of asphalt, are produced through vacuum tower distillation processing at petroleum refineries primarily to increase the production of higher value lighter components such as gasoline and jet fuel. From this process, the majority of saturates are removed in VTB, thus making them very stiff. Due to this, there is very limited use for VTB in paving applications. In this work, it was shown that heat-bodied linseed oil (HBO), and partially hydrogenated heat-bodied linseed oil (PHBO) when used together show improved low-temperature binder and mix performance compared to a control VTB group, and two control groups (performance grades – PG 64-22 and PG 70-22) using the bending beam rheometer and the semi-circular bend test. Furthermore, when the linseed oil-derived materials in used combination are compared against an available commercial rejuvenator at two dosage levels using the semi-circular bend (SCB) test at low temperatures they perform better than the commercially available rejuvenator in terms of fracture energy at low temperature.