Abstract:

As there is no generally accepted and reasonable index to evaluate the low-temperature performance of asphalts and asphalt mixtures at present,this paper introduces the glass transition temperature for the evaluation.In the proposed method,first,dynamic frequency sweep tests are performed using dynamic shear rheometer AR-2000 in the linear visco-elastic range for different asphalts and asphalt mixtures.Then,the glass transition temperatures of different asphalts and asphalt mixtures are obtained by analyzing the sweep test results based on the time-tempera-ture superposition principle,and the results are further verified by the low-temperature bend creep test of asphalt mixtures.The results show that,with a clear physical meaning,the glass transition temperature obtained by dynamic frequency sweep tests accords well with the practical one;and that the glass transition temperatures of asphalts and asphalt mixtures have good relation to the low-temperature bend broken strain of asphalt mixtures.It is thus concluded that the glass transition temperature is suitable for evaluating the low-temperature performance of asphalts and asphalt mixtures.

Key words: asphalt mixture, glass transition temperature, master curve, low-temperature performance, dynamic shear rheometer