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

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.