就地热再生沥青混合料的动态力学特性

Dynamic Mechanical Properties of Hot-in-Place Recycled Asphalt Mixtures

为探究就地热再生沥青混合料动态力学特性,采用动态剪切流变试验和弯曲流变试验确定了再生剂最佳掺量,并对就地热再生混合料(RAC-13)及SBS(苯乙烯-丁二烯-苯乙烯三嵌段共聚物)改性沥青混合料(AC-13、SMA-13)在4种温度及6种频率下进行单轴压缩动态模量试验,同时结合时温等效原理和CAM(Christensen-Anderson-Marasteanu)模型构建了沥青混合料动态模量与相位角主曲线并分析了其力学性能。结果表明:就地热再生沥青混合料动态模量随频率增加(或温度降低)而增大,相位角随频率增加(或温度降低)先升高后降低。在标准设计条件(20℃、10 Hz)下,就地热再生沥青混合料动态模量分别是AC-13、SMA-13的1.6、1.1倍,其具有优异的抗高温抗变形能力且低温抗裂性与SMA-13相当。CAM模型可以拟合得到就地热再生沥青混合料动态模量与相位角在宽频范围内的发展规律,为就地热再生沥青路面结构计算提供参考。

In order to explore the dynamic mechanical properties of hot-in-place recycled asphalt mixture,the optimal dosage of regenerant was determined by dynamic shear rheological test and bending rheological test.The uniaxial compression dynamic modulus test was carried out on the hot-in-place recycled mixture(RAC-13)and SBS modified asphalt mixture(AC-13,SMA-13)at 4 temperatures and 6 frequencies.At the same time,the dynamic modulus and phase angle master curves of the asphalt mixture were constructed by combining the time-temperature equivalence principle and the CAM(Christensen-Anderson-Marasteanu)model,and its mechanical properties were analyzed.The results show that the dynamic modulus of the hot-in-place recycled asphalt mixture increases with increasing frequency(or decreasing temperature),and the phase angle first increases and then decreases with increasing frequency(or decreasing temperature).Under the standard design conditions(20℃,10 Hz),the dynamic modulus of the hot-in-place recycled asphalt mixture is 1.6 and 1.1 times that of AC-13 and SMA-13,respectively.It has excellent high temperature deformation resistance and low temperature crack resistance is equivalent to SMA-13.The CAM model can be fitted to obtain the development law of the dynamic modulus and phase angle of the hot-in-place recycled asphalt mixture in a wide frequency range,which provides a reference for the calculation of the structure of the hot-in-place recycled asphalt pavement.