Effect of binder modification and thermal conditioning on asphalt binder rheology

摘要

Permanent deformation is a common distress associated with a flexible pavement system. Virgin binders when unmodified cannot sustain detrimental environmental effects and heavy traffic loading. The environmental effects imposed on field pavements, for our experiments, were simulated by novel equipment called Thermal cycler. This simulates the conditioning of field pavements effectively and efficiently. Different modified blends of Elvaloy, Sulfur, and Eaton reagent were considered to study their effect on permanent deformation of asphalt binder, and their relative variation in G* was evaluated at different conditioning times. A Dynamic Shear Rheometer was used to assess different performance parameters for the evaluation of their rheological properties. It was observed that virgin binder is very sensitive to temperature variations and conditioning time. The rate of increase in failure temperature was higher for a virgin binder. Elvaloy modified bitumen showed more resistance to thermo-oxidative aging followed by Sulfur. The percentage increase in G* was 70% and 224% for Elvaloy and virgin binder, respectively. At the same value of PG 64, Elvaloy modified bitumen showed more resistance to permanent deformation as compared to Sulfur and Eaton reagent.