Direct determination of relaxation modulus from testing involves difficulties in testing operation and may cause large errors.Storage modulus master curve for Superpave 20 asphalt mixture were developed according to time temperature superposition principle using storage modulus from complex modulus testing results at various temperatures and frequencies.The storage modulus was converted to relaxation modulus by using collocation method and viscoelastic theories.The parameters of Prony series representations for relaxation modulus were determined.The results show that relaxation modulus over 10-8108s can be obtained for asphalt mixtures using simple complex modulus testing.The Prony series representations for relaxations modulus correspond to Wiechert mechanical models and they are expressed in exponential series form.The results provide great conveniences in the analysis of viscoelastic mechanical behavior of asphalt mixtures.
