In order to analyze the impact of reclaimed asphalt pavement( RAP) on viscoelastic response and fatigue performance of hot mix asphalt ( HMA ) , different RAP content ( 10%, 20%, 30%) and gradation (AC-13、AC-16) of HMA were designed. The dynamic modulus and phase angle at different temperature and loading frequencies were obtained by using the asphalt mixture performance tester ( AMPT) , and then using time-temperature superposition principle the dynamic modulus master-curve of different asphalt mixtures were obtained. After that, uniaxial tensile fatigue test was conducted on different asphalt mixtures, and the damage characteristic curve ( C-S) and energy-based failure criterion with experimental cycles to failure ( GR-Nf ) were determined by using simplified viscoelastic continuum damage ( S-VECD) model. The results show that the dynamic modulus of asphalt mixture decreases with the increasing temperature and the decreasing loading frequency. Lower temperature and higher frequency, the asphalt mixture more like elasomer, otherwise, it likes viscous substance. The mastercurve of asphalt mixture shows that the higher RAP content is, the larger dynamic modulus is, but there is no significant difference. The fatigue test shows that with the RAP content increase, the fatigue performance decreases, which means the lower relaxation ability. So the fatigue performance should be paid more attentionta, when higher RAP content is used.%为了分析废旧沥青路面材料( RAP)对热拌沥青混合料的黏弹性动态响应及疲劳性能的影响,设计了不同RAP掺量(10%、20%、30%)及不同级配(AC-13和AC-16)的沥青混合料,采用沥青混合料性能试验仪(AMPT)在不同温度和加载频率下的动态模量,之后采用时间-温度等效原理,确定了不同沥青混合料的动态模量主曲线；并对不同沥青混合料进行了单轴拉伸疲劳试验,通过简化的黏弹性连续损伤模型( S-VECD),确定了不同级配、不同RAP含量的沥青混合料的损伤特征曲线( C-S),及基于能量的疲劳失效标准与疲劳加载次数之间的关系( GR-Nf )。结果表明：沥青混合料的动态模量随着温度的升高、加载频率的降低而降低,温度越低、频率越高,沥青混合料越接近弹性体,反之越接近黏性体；从不同级配的沥青混合料的动态模量主曲线中可以看出,RAP含量越高,其动态模量越高,但总体来看相差不大。疲劳试验及分析表明：RAP含量较高时,其疲劳性能较低,表明其应力松弛能力较差,因此应更加关注再生沥青混合料的抗疲劳性能。
展开▼
