Binder Rheology Based Dynamic Modulus and Phase Angle Predictive Models for Asphalt Concrete

摘要

This study proposes new regression-based predictive models to estimate dynamic modulus and phase angle of asphalt concrete from the dynamic shear modulus and phase angle of the asphalt binder used in the asphalt mixture. Other parameters related to the aggregate gradation and mixture volumetric are also incorporated in these models. A total of 10 asphalt concrete mixes with 4 asphalt binders having different performance grades and sources were used in this study. The loose asphalt-aggregate mixtures were compacted and cored to cylindrical specimens. Three cylindrical specimens from each of the asphalt-aggregate mixtures were prepared and tested in the laboratory for dynamic modulus and phase angle at different test temperatures and loading frequencies. For all the test specimens, dynamic modulus and phase angle mastercurves at 70 °F reference temperature were generated by applying time-temperature superposition principle. The collected binders were tested for dynamic shear modulus and binder phase angle using dynamic shear rheometer. Also for the binder, the dynamic shear modulus and phase angle mastercurves were generated by applying time-temperature superposition principle. Non-linear optimization process was used to evaluate the model parameters. Statistical analysis showed that a fairly accurate estimation of dynamic modulus as well as phase angle of asphalt concrete as a function of temperature and loading frequency can be found by using these new predictive models.