Evaluating the Effect of Polymer Modification on the Low-Temperature Rheological Properties of Asphalt Binder

Abstract

This paper investigates the viscoelastic properties of oxidized neat bitumen and threepolymer-modified binders at low temperatures. The earlier proposed interrelated expressions forthe relaxation modulus and for the creep compliance of bitumen binders are further developed.The results of creep testing of the binders on a bending beam rheometer at the six temperaturesfrom -18°С to −36°С are presented. The results were analyzed using the equations developed forthe relaxation modulus and the relaxation time spectrum. Viscosities at the low temperatures oftested binders were estimated. Approximate interrelations between the loss modulus and the relaxationspectrum were presented. The method for the determination of the glass transition temperatureof a binder in terms of the relaxation time spectrum is proposed. The glass transitiontemperatures of tested binders were determined by the proposed method and compared with onesdetermined by the standard loss modulus-peak method.