不同类型高模量沥青混合料抗剪性能研究

为了研究不同类型高模量沥青混合料抗剪性能,利用Superpave剪切试验机并按恒高度频率扫描试验(FSCH)方法测得了EME2沥青混合料和AC-20沥青混合料的复数剪切模量及相位角,根据时间-温度等效原理,利用非线性最小二乘法拟合得到了参考温度下的复数剪切模量主曲线,预测了两种高模量沥青混合料的高低温性能。通过恒高度重复剪切试验(RSCH)得到了两种高模量沥青混合料的加载末应变和剪切斜率。FSCH结果表明,两种沥青混合料的复数剪切模量均随温度的升高而降低,随荷载频率增加而增加,AC-20沥青混合料的高温抗剪性能优于EME2沥青混合料,EME2沥青混合料的常温抗变形能力优于AC-20沥青混合料;RSCH结果表明,在60 ℃条件下,AC-20沥青混合料的抗剪性能优于EME2沥青混合料。

Shear Performance of Different Types of High Modulus Asphalt Mixtures

In order to study the shear performance of different types of high modulus asphalt mixtures, the complex shear modulus and phase angle of EME2 asphalt mixture and AC-20 asphalt mixture were measured by Superpave shear testing machine according to frequency sweep test at constant height (FSCH) method. According to the time-temperature equivalent principle, the complex shear modulus master curves at reference temperature were obtained through non-linear least square regression analysis, and the master curves were used to predict the high and low temperature performance of the two types of asphalt mixtures. Through the repeated shear test at constant height (RSCH), the end load strain and shear slope of two high modulus asphalt mixtures were obtained. The FSCH results show that the complex shear modulus of the two asphalt mixtures decreases with the increase of temperature and increases with the increase of load frequency. The high temperature shear performance of AC-20 asphalt mixture is better than that of EME2 asphalt mixture, and the normal temperature deformation resistance of EME2 asphalt mixture is better than that of AC-20 asphalt mixture. The RSCH results show that the shear performance of AC-20 asphalt mixture is better than that of EME2 asphalt mixture at 60 ℃.