Use of modified slow tire pyrolysis product as a rejuvenator for aged bitumen

• Slow pyrolysis of scrap tires was performed.
• Pyrolytic product was successfully used as a rejuvenator for aged bitumen.
• Non-aged and aged bitumen samples were mechanically and rheologically evaluated.
• Interconversion between material functions was completed.
• Pyrolytic product rejuvenated properties of aged bitumen.

Effect of the addition of the pyrolytic product to aged bitumen was studied. Rejuvenator was prepared from scrap tire crumb modified pyrolytic condensate. Polycyclic aromatic hydrocarbons content in the pyrolysis condensate was kept low by applying relative low process temperature; the highest treatment temperature was 500 °C, similarly to those reported in existing studies. 50/70 penetration grade laboratory aged bitumen, prepared by using rolling thin film oven test and accelerated pressure ageing procedure, was used as reference bitumen. The influence of various concentrations of rejuvenator (3%, 5%, 10% and 20%) on the aged and non-aged bitumen was evaluated by standard mechanical and rheological tests. Rheological measurements were performed in the intermediate range by dynamic shear rheometer and in low temperature range with bending beam rheometer. Mechanical functions, dynamic shear modulus G(ω) and creep compliance D(t), calculated from the rheological test were interconverted to shear G(t) and tensile E(t) relaxation modulus. The results confirmed the suitability of the rejuvenator for modification of the aged bitumen.