Laboratory Evaluation of Oil- Extended SBS Modified Binder

Oil-extended styrene-butadiene-styrene (SBS) was used to modify asphalt binders. The modified binder samples were produced at three aging states (original, short-term aged, and long-term aged) using a rolling thin film oven (RTFO) and pressure aging vessel (PAV). Superpave asphalt binder tests were conducted to evaluate the physical and rheological properties of the modified binders. From the results, (1) the addition of oil-extended SBS has a positive effect on workability with lower viscosity, which showed a viscosity of less than 3000 cP at 135 degrees C, compared to the binders modified with the conventional SBS, (2) the asphalt binders with oil-extended SBS showed enhanced rutting resistance based on improved viscoelastic properties, which revealed that adding 8% oil-extended SBS was satisfied at 76 degrees C for G*/ sin delta, and (3) the oil-extended SBS modifier showed to significantly improve not only the high-temperature properties, but especially the low-temperature cracking resistance, decreasing the G*circle sin delta and stiffness.