Characterizing the low-temperature viscoelastic behavior of asphalt mixtures: A comparative study

Thermal cracking is a critical pavement issues in the cold regions and has been of a major concern in asphalt pavements. The paper presents a viscoelastic modeling work using pure power law, generalized power law, and Prony series functions to characterize low temperature performance of asphalt mixtures. The bending beam rheometer (BBR) using asphalt mixture beams was employed to obtain creep compliance and further viscoelastic analyses were performed to determine relaxation moduli and thermal stresses of asphalt mixtures. The objective of this paper is to provide a better understanding on low temperature viscoelastic behavior of asphalt mixtures by quantifying creep compliance errors and differences among these representation models (pure power law, generalized power law, and Prony series functions) in the predictions of relaxation moduli and thermal stresses. Based on the comparison of viscoelastic analyses at low temperatures, the generalized power law function shows a better agreement with the experimental data and has the least creep compliance error as compared with other two representation functions.