New testing protocols and data analysis methods were developed to characterize the anisotropicviscoelastic properties of undamaged asphalt mixture which was characterized using three complexmoduli and three complex Poisson’s ratios. These six parameters were obtained by three nondestructivecreep test scenarios: i) uniaxial compressive test, ii) uniaxial tensile test, and iii) indirect tensile test. Theelastic-viscoelastic correspondence principle was employed to derive the frequency-dependent magnitudeand phase angle of the six complex variables whose master curves were constructed by using proposedmaster curve models and conducting the three tests at three temperatures on 16 specimens varying at airvoids, binder types and aging periods. As expected, the undamaged asphalt mixtures showed significantdifferences in compression and in tension. Specifically, the phase angle of the tensile complex moduluswas significantly greater than that of the compressive complex modulus. In addition, the undamagedasphalt mixture exhibited distinctly anisotropic properties in compression. Calculations demonstrated themagnitude of the vertical compressive complex modulus was about 1.2 ~ 2 times larger than themagnitude of the horizontal compressive complex modulus.Compared to traditional anisotropic tests using multiple specimens cored in different directions,the newly proposed test protocols were more efficient. Firstly, no dynamic tests but creep tests wererequired to obtain the complex moduli and complex Poisson’s ratios. Secondly, only one cylindricalspecimen was needed to conduct all three of the tests, which eliminated sample to sample error andreduced the quantity of the testing materials. Thirdly, each test was finished in one minute. Finally, strainswere limited to less than 100 microstrains which assumes and verifies that no damage was introduced tothe specimens that can then be reused in subsequent destructive tests.
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