Abstract:

In this paper, the measurement and analysis methods of the dynamic modulus of asphalt mixture are investigated based on the indirect tensile test mode, with two kinds of asphalt mixtures commonly used in China as the research objects. On the basis of the GPM testing mode and by taking into account the effects of the biaxial plane stress assumption and the specimen surface bulging, the dynamic modulus of indirect tension is determined according to the corrected strain and stress. Then, according to the principle of time-temperature conversion, the maximum dynamic modulus of the mixture is estimated based on the Hirsch model. Moreover, the Global Aging model and the Arrhenius model are used to obtain the shrift factors. The master curves of the dynamic modulus at 20 ℃ and their Sigmodial functions are finally determined by numerical optimization. It is found from the master curves that the loading frequency and temperature dependences of asphalt mixture AC-20 are weaker than those of AC- 13C, especially in the low-frequency stage.

Key words: asphalt mixture, indirect tension, dynamic modulus, master curve, phase angle