高寒大温差条件下沥青混合料低温性能研究

Research on Low Temperature Performance of Asphalt Mixture under Cold and Large Temperature Difference

为研究高寒、大温差以及降温速率等因素综合作用下的沥青混合料低温性能,在室内模拟高寒大温差条件,通过变化沥青类型、用量、级配等因素制备多种沥青混合料,利用约束试件温度应力试验(TSRST)、低温弯曲试验、冻融劈裂试验等研究沥青混合料在高寒大温差条件作用下低温性能的变化规律。研究结果表明:在高寒、大温差作用条件下,沥青混合料类型对其低温性能存在显著影响,SMA类沥青混合料冻断温度低于AC类沥青混合料,3种混合料的低温性能由高到低依次为SMA-13>AC-13>AC-16;沥青类型对沥青混合料低温性能存在显著性影响,其中SBS改性沥青>SBR改性沥青>基质沥青;此外,高寒大温差条件对沥青混合料强度及水稳定性有显著的影响。研究成果可以为青藏高原等高寒大温差地区沥青路面面层混合料的优化设计提供依据。

In order to study the low-temperature performance of asphalt mixture under the comprehensive effects of cold,large temperature difference and cooling rate,various asphalt mixtures are prepared by changing asphalt types,dosage,gradation and other factors.The TSRST,low-temperature bending test and freeze-thaw splitting test are carried out to study the change rule of low-temperature performance of asphalt mixture under the action of cold and large temperature difference.The results show that under the action of cold and large temperature difference,the types of asphalt mixture have significant influence on its low temperature performance,the frozen break temperature of SMA asphalt mixture is lower than that of AC asphalt mixture,and the low temperature performance of the three mixtures is SMA-13>AC-13>AC-16 from high to low;asphalt types have significant influence on the low temperature performance of asphalt mixture,in which SBS modified asphalt>SBR modified asphalt>matrix asphalt.In addition,the cold and large temperature difference conditions have a significant impact on the strength and water stability of asphalt mixture.The study results can provide basis for the optimization design of asphalt pavement surface mixture in Qinghai-Tibet Plateau and other cold areas with large temperature difference.