高模量与高黏沥青老化前后动态力学性能研究

Research on Dynamic Mechanical Properties of High Modulus Asphalt and High-viscosity Asphalt before and after Aging

为研究高模量、高黏沥青老化前后动态力学流变特性,优化性能评价指标,利用动态剪切流变仪(DSR)和弯曲梁流变仪(BBR)对原样、RTFOT和PAV沥青进行了黏弹性能、抗车辙性能、抗疲劳性能及抗裂性能测试。结果表明:储能模量G'、损耗因子tanδ以及延迟弹性恢复指标εp/εL能够准确评价不同类型沥青老化前后力学性能,其中高模量沥青抗车辙能力和延迟恢复抗变形能力最佳,而高黏沥青抗疲劳和低温抗裂能力最优;但沥青抗老化能力基于不同力学流变指标的分析结果而异,对低温指标,高黏沥青优于高模量沥青,中、高温指标则相反。总之,对高模量、高黏等特征性显著的沥青建议选择合理试验参数,增加PAV或延长老化等作用条件,结合主导因素指标进行综合评价。

In order to study the dynamic mechanical rheological properties of high modulus asphalt and highviscosity asphalt before and after aging, and optimize their property evaluation index, the viscoelastic property, rutting resistance, fatigue resistance and crack resistance of original asphalt, RTFOT asphalt and PAV asphalt are tested by dynamic shear rheometer （DSR） and bending beam rheometer （BBR）. The result shows that （ 1 ） storage modulus G＇ loss factor tan δ and delayed elastic recovery index εp/εL can accurately evaluate the mechanical properties of different types of asphalt before and after aging, among them, the antirutting ability and delayed recovery anti-deforming capability of high modulus asphalt are best, the fatigue and low-temperature crack resistance of high-viscosity asphalt is the most optimal ; （2） the anti-aging performance of 2 types of asphalt are different according to the results of analysing different mechanical rheological indicators, the low-temperature indicators of high-viscosity asphalt is better than those of high modulusasphalt, while the medium and characteristic asphalt such as high reasonable experimental parameters, temperature indicators are inferi ulus asphalt and high-viscosity as PAV or postpone the aging time, or. Above all, for phalt, it is suggested and combine with the significant to select dominant factor indexes for comprehensive evaluation.