Nonlinear Rheological Characteristics Of Fine Aggregate Matrix Based On Ft-Rheology

The fine aggregate matrix (FAM) is an important part of asphalt mixture, which has attracted much attention in recent years. The linear rheological properties of FAM have been well analyzed. However, asphalt pavements may also support loading in the nonlinear regime during its service. To comprehensively understand the rheological properties of FAM, their nonlinear rheological characteristics were tested by the large amplitude oscillatory shear test (LAOS) and analyzed by Fourier Transform (FT)-rheology. The nonlinear rheological characteristics of FAM were analyzed based on I-3/I-1, Q(0) and Chebyshev coefficients. The effects of asphalt types, nominal maximum aggregate size (NMAS) and air voids on the nonlinearity of FAM were also investigated. The results reveal that the nonlinear rheological property of FAM is more significant than that of binders. I-3/I-1 of FAM firstly increases and then tends towards the plateau region with an increase in stress. And I-3/I-1 of FAM increases with decreasing frequency. The nonlinearity of unmodified FAM is obviously lower than that of modified FAM. The nonlinearity of FAM increases with increasing NMAS and decreasing air void. All studied FAM samples show stress softening and shear thinning behaviors under the studied test conditions. (C) 2020 Elsevier Ltd. All rights reserved.