复合多聚磷酸改性沥青混合料动态力学性能

Dynamic mechanical properties of composite polyphosphate modified bitumen mixture

为研究多聚磷酸(polyphosphoric acid,PPA)+SBS复合改性沥青混合料的动态力学性能,采用单轴压缩动态模量试验,分析温度和频率对动态模量和相位角的影响,并基于改进Havriliak-Negam(i HN)模型构建动态模量和相位角主曲线,同时与SBS改性沥青混合料相对比。结果表明:2种沥青混合料动态模量和相位角随温度和频率的变化呈现相同的趋势,HN模型可准确拟合2种沥青混合料的动态模量和相位角主曲线。相较于SBS改性沥青混合料,PPA+SBS复合改性沥青混合料的相位角在-10、20、50℃时均降低,而动态模量在-10℃时降低,20℃时变化较小,50℃时增加;较宽频域范围内,PPA+SBS复合改性沥青混合料在高温低频下动态模量变大,相位角变小,在低温高频下动态模量变小,相位角变化不大;PPA+SBS复合改性沥青混合料具有更优的动态力学性能。

In order to investigate the dynamic mechanical properties of polyphosphoric acid(PPA)and SBS co-modified asphalt mix⁃tures,uniaxial compression dynamic modulus tests were conducted.The influences of temperature and frequency on the dynamic modulus and phase angle were analyzed.Additionally,dynamic modulus and phase angle master curves were constructed based on the modified Havriliak-Negami(HN)model.A comparative analysis was also performed with SBS-modified asphalt mixtures.The results indicate that both types of asphalt mixtures exhibit similar trends in dynamic modulus and phase angle variations with changes in temperature and frequency.The HN model accurately fits the master curves of dynamic modulus and phase angle for both asphalt mixtures.In comparison to SBS-modified asphalt mixtures,the phase angle of PPA+SBS co-modified asphalt mixtures decreases at-10,20,and 50℃,while the dynamic modulus decreases at-10℃,changes minorly at 20℃,and increases at 50℃.Over a wide frequency range,PPA+SBS co-modified asphalt mixtures exhibit increased dynamic modulus and decreased phase angle at high temperatures and low frequencies,while they show decreased dynamic modulus and relatively stable phase angle at low tempera⁃tures and high frequencies.These findings suggest that PPA+SBS comodification endows asphalt mixtures superior dynamic mechanical properties.