Investigation of asphalt binder and asphalt mixture low temperature creep properties using semi mechanical and analogical models

• DIP analysis provides good agreement between generated and original asphalt images.
• Linear relation was observed between Logτbinder and Logτmix based on Huet model.
• ENPTE parameter α is a unique value for binder and corresponding mixture.
• An expression for parameter α was developed based on Hirsch and Huet models.
• The new expression for α provides good estimations of the experimental data.

The Hirsch model and the ENTPE transformation are commonly used to predict asphalt mixture creep stiffness from asphalt binder creep stiffness data and vice versa, at low temperatures. However, they present accuracy limits and lack of understanding on the physical parameters meaning, respectively. This paper presents an experimental and theoretical investigation to establish a link between the microstructure of mixtures and these parameters. This is accomplished by three-point bending tests on asphalt binders and mixtures, digital image analysis and through a newly derived expression of the α parameter in the ENTPE transformation. The results indicate that reasonable predictions of binder low temperature creep properties can be obtained from the corresponding mixture low temperature creep properties.