基于灰色关联分析的树脂与弹性体高黏沥青高温性能评价

High-temperature performance evaluation of resin and elastomer high viscosity asphalt based on grey correlation analysis

通过透射电子显微镜扫描(TEM)、流变试验,以及常规性能测试,分析树脂高黏沥青与弹性体高黏沥青的路用性能及改性机理。采用流变仪分别进行不同掺量(3%、5%、8%)下两种高黏沥青的多重应力蠕变恢复试验(MSCR)、温度扫描试验和动态频率扫描试验,并采用Cross模型和Carreau模型对动态频率扫描结果进行拟合,得到沥青60℃零剪切黏度(ZSV)。进一步对高黏沥青胶结料试验指标与车辙动稳定度进行灰色关联分析。结果表明:树脂类高黏改性沥青主要由内部形成的结晶体起到增黏效果,弹性体改性沥青由改性剂与基质沥青形成的三维弹性结构起到增黏效果;树脂类高黏改性沥青在线性弹性区间有很好的改性效果,但在非线性弹性区间由于结晶体熔化,改性效果不如弹性体高黏沥青;Cross模型得到的ZSV拟合值大于Carreau模型;高黏沥青软化点和蠕变恢复率与沥青混合料车辙动稳定度有显著相关性,可以很好地评价高温路用性能,而不可恢复蠕变柔量和相位角的相关性较差。

The pavement performance and modification mechanism of resin-based high-viscosity asphalt and elastomer-based high-viscosity asphalt were analyzed using various methods including transmission electron microscope scanning(TEM),rheological tests,and regular performance tests.The multiple stress creep recovery test(MSCR),temperature sweep test,and dynamic frequency sweep test were conducted on the two high-viscosity asphalts at different contents(3%,5%,8%)with the rheometer.The results of the dynamic frequency sweep were fitted using the Cross model and the Carreau model respectively to determine the zero shear viscosity(ZSV)of the asphalt at 60°C.Furthermore,grey correlation analysis was applied to assess the relationship between the test indexes of the high-viscosity asphalt binder and its rutting stability.The findings indicate that the resin-based high-viscosity modified asphalt is primarily composed of internally formed crystals that can enhance viscosity,while the elastomer-based modified asphalt exhibits a three-dimensional elastic structure created by the modifier and base asphalt to increase viscosity.The resin-based high-viscosity modified asphalt appears a favorable modification effect in the linear elastic interval,but in the nonlinear elastic interval,its modification effect is inferior to that of the elastomer-based high-viscosity asphalt due to crystal melting.The ZSV fitting value obtained from the Cross model is higher than that from the Carreau model.The softening point and creep recovery rate of the high-viscosity asphalt exhibit a significant correlation with the rutting stability of the asphalt mixtures,which is appropriate to evaluate the high-temperature pavement performance.However,the non-recoverable creep compliance and phase angle show a relatively weak correlation.