Viscoelastic Transition of Unaged and Aged Asphalt

Abstract

This investigation reports the viscoelastic solid to fluid transition of asphalt as the temperature is varied. Air blown, blended asphalt and pitch obtained from Arab mix crude were tested under unaged, short-term aged, and long-term aged conditions. All the materials were subjected to two experimental protocols in the 20–50°C temperature region. In the first experimental protocol, the material was subjected to frequency sweep in small amplitude oscillatory shear and in the second protocol the material was subjected to large deformation stress relaxation. From the analysis of the experimental results, it was seen that asphalt exhibited a viscoelastic solid regime, a viscoelastic fluid regime, and a transition regime in the temperature range tested. In the small amplitude oscillatory shear, the transition regime was captured using a frequency-dependent storage modulus (