Rutting Analysis of Pyrolytic-Oil-Modified Bituminous Binders Using MSCR

Permanent deformation is the major defect that the flexible pavement industry needs to tackle, which occurs due to the heavy traffic and environmental conditions. Research is being done all over the world to overcome this problem by using various modifiers in bituminous binders, polymer modification of binders being the most common. The multiple stress creep and recovery (MSCR) test had been recommended recently to analyse the resistance to rutting of bituminous binders. MSCR has been proven to be superior, as compared to the Superpave rutting factor (G*/sinδ), in characterising the rutting behaviour of unmodified as well as modified binders. The current study intended to characterise the rutting resistance performance of HDPE pyro-oil-modified asphalt binders using MSCR test. In this paper, the viscosity graded bitumen (VG30) is used as the base bitumen. Ethylene vinyl acetate (EVA) copolymer is used to prepare the polymer-modified bitumen. 5% and 6% EVA by weight of base bitumen is used to modify the binders, and 1% HDPE pyro-oil by weight is used to further modify the base and polymer-modified binders. The MSCR test at 50, 60 and 70 °C is done on the unmodified and modified binders to evaluate their rutting resistance.