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选择3种沥青混合料进行不同试验条件下的沥青混合料性能试验(AMPT),分析了加载频率及试验温度对沥青混合料黏弹性动态响应的影响;并采用Sigmoidal模型,得到了沥青混合料的动态模量移位因子及模型参数,形成并分析了沥青混合料动态模量和相位角主曲线。结果表明,随着加载频率的升高,沥青混合料的动态模量逐渐增大,但温度越高,增加幅度越小;动态模量随着加载频率增大,在较低的温度下(5℃和15℃)符合对数增长关系,在较高的温度下(45℃和55℃)符合线性增长关系,但超过45℃后,不同加载频率的动态模量差异较小。不同加载频率的相位角最大值对应的温度不同,加载频率越低,对应的温度也越低。动态模量主曲线和移位因子可以较好地描述加载频率和试验温度对沥青混合料黏弹性动态响应的影响。在低温高频状态下,矿料级配对沥青混合料动态模量的贡献较大;而在高温低频状态下,沥青逐渐软化,结合料对混合料动态模量的影响更为显著。
The asphalt mixture performance test (AMPT) under different test conditions was selected, and the influence of loading frequency and test temperature on the dynamic response of asphalt mixture viscoelasticity was analyzed. By using Sigmoidal model, Dynamic modulus displacement factor and model parameters, the formation and analysis of asphalt mixture dynamic modulus and phase angle of the main curve. The results show that with the increase of loading frequency, the dynamic modulus of asphalt mixture gradually increases, but the higher the temperature, the smaller the increase; the dynamic modulus increases with the loading frequency, at a lower temperature (5 ℃ and 15 ℃, respectively. The logarithmic increase was in line with the linear increase at higher temperatures (45 ℃ and 55 ℃), but the difference of dynamic modulus at different loading frequencies was smaller than 45 ℃. The maximum phase angle corresponding to different loading frequencies corresponds to different temperatures. The lower the loading frequency is, the lower the corresponding temperature is. The dynamic modulus main curve and displacement factor can describe the effect of loading frequency and test temperature on the viscoelastic dynamic response of asphalt mixture. In the condition of low temperature and high frequency, the mineral aggregate gradation contributes a lot to the dynamic modulus of asphalt mixture; while in the condition of high temperature and low frequency, the asphalt softens gradually, the effect of binder on the dynamic modulus of the mixture is more significant.