Experimental and analytical methods for evaluating the high temperature viscoelastic properties of fine aggregate matrix

A fine aggregate matrix (FAM) is the main component of an asphalt mixture, and its high temperature rheological property is well related to the rutting potential of asphalt pavements; therefore, it is necessary to investigate the high temperature rheological behavior of FAM. To this end, a modified multiple stress creep recovery test is utilized for assessing the rheological properties of FAM. A new creep-recovery model (CRM) that can better describe the creep recovery behavior of FAMs is proposed herein. A comparison of the values calculated using the CRM, Burgers, and fractional derivative models showed that the CRM performed the best. Two sets of indicators are proposed for evaluating the high-temperature rheological properties of the FAM. Three types of asphalt binders were used to fabricate the FAM samples to verify the applicability of these evaluation indicators. According to experiments and data analysis results, the two sets of evaluation indicators were consistent in evaluating the high-temperature rheological properties of FAM. The rheological properties of different FAMs were analyzed at the shear damage-development stage, and the results revealed significant fluctuations in the viscoelasticity of the FAM prepared with asphalt binder possessing an elevated high-temperature performance grade. Further, the high-temperature stability of the FAM weakened as the number of loads increased, and the damage resulting from this process affected the high-temperature stability of the FAM to the same extent as the creep and recovery processes.