Characterization of the Complex Moduli for Asphalt-aggregate Mixtures at Various Temperatures

Constitutive properties of asphalt-aggregate mixtures are modelled very often applying viscoelastic models represented by rheological schemes. The parameters of these schemes are identified using cyclic test at various temperatures. The procedure leads to the dynamic modulus master-curve. The sigmoidal model is applied in order to represent the master-curve usually, but such a model does not have real physical meaning. The objective of the paper is to demonstrate the method of characterization of the complex moduli for bituminous mixtures using classical and fractional rheological models. Fractional models give the possibility to characterize the response of asphalt materials with a small number of elements. In order to find the parameters of rheological schemes, the optimization problem is formulated. The solution is obtained using least-squares methods implemented in MATLAB software.