基于玻璃化转变温度的沥青混合料低温性能研究

Investigation into Low-Temperature Performance of Asphalt Mixtures Based on Glass Transition Temperature

鉴于目前尚未有公认、合理的沥青和沥青混合料低温性能评价指标,提出采用玻璃化转变温度来进行评价.采用动态剪切流变仪AR-2000对不同沥青和沥青混合料在线粘弹范围内进行了动态频率扫描;应用时温等效原理对频率扫描结果分析得到不同材料的玻璃化转变温度,并用沥青混合料低温弯曲试验进行验证.结果表明,由动态频率扫描测试得到的玻璃化转变温度符合路面实际情况,且物理意义明确,沥青和沥青混合料的玻璃化转变温度与混合料低温弯曲破坏应变相关性良好.因此,玻璃化转变温度可用于评价沥青和沥青混合料的低温性能.

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.